Disorders of Liver, Biliary Tract, Pancreas, and Spleen
Accessory Spleen
| Incidence: |
10–30% of population; multiple (up to 6) in 10% |
| Cx: |
disease recurrence due to hypertrophy of accessory spleen after splenectomy for hypersplenism |
Ampullary Tumor
| Age: |
6th + 7th decade; M:F = 2:1 |
| Path: |
average diameter of <3 cm |
| Histo: |
(a) dysplastic epithelium in glandular/villous structures of tubular/villous adenoma
(b) carcinoma in situ
(c) invasive carcinoma often with desmoplastic reaction |
| Associated with: |
familial adenomatous polyposis syndromes (eg, familial polyposis coli, Gardner syndrome) [100–200-fold risk], colon carcinoma |
malaise, epigastric pain, weight loss
intestinal bleeding (tumor ulceration)
intermittent jaundice (ductal obstruction)
gray “aluminum/silver-colored” stools (3%)
chills, fever, RUQ pain (ascending cholangitis) in up to 20%
endoscopy: tumor extending through orifice (63%), prominent papilla/submucosal mass (25%), not visualized (9%)
TNM staging:
| T1: |
tumor confined to ampulla |
| T2: |
tumor extending into duodenal wall |
| T3: |
invasion of pancreas <2 cm deep |
| T4: |
invasion of pancreas >2 cm deep |
International Union Against Cancer Staging:
| I = |
tumor confined to ampulla |
| II = |
tumor extension into duodenal wall/pancreas |
| III = |
regional lymph node involvement (Lnn stations around head + body of pancreas, anterior + posterior pancreaticoduodenal, pyloric, common bile duct, proximal mesenteric) |
| IV = |
invasion of pancreas >2 cm deep |
| Rx: |
Whipple procedure (= pancreaticoduodenectomy) |
| Prognosis: |
28–70% 5-year survival for ampullary carcinomas (depending on stage) |
| DDx: |
- 1. Periampullary duodenal adenoma/adenocarcinoma (usually larger lesion with significant intraduodenal extension)
- Choledochocele (cystic lesion filling with biliary contrast)
- Brunner gland tumor, pancreatic rest (“myoepithelial hamartoma”), leiomyoma, carcinoid (often produce somatostatin)
- Duodenitis, pancreatitis
- 5. Stone impaction in ampulla
|
Annular Pancreas
| Incidence: |
1:20,000 autopsies |
| Age at discovery: |
childhood (52%); adulthood (48%) |
| Associated with: |
other congenital anomalies (in 75%):
esophageal atresia, TE fistula, duodenal atresia/stenosis, duodenal diaphragm, imperforate anus, malrotation, Down syndrome |
| Location: |
2nd portion of duodenum (85%);
1st/3rd portion of duodenum (15%) |
| • neonate: |
persistent vomiting (duodenal obstruction) |
| • adult: |
nausea, vomiting (60%), abdominal pain
(70%), hematemesis (10%), jaundice (50%) |
| Cx: |
increased incidence of
- periampullary peptic ulcers
- pancreatitis (15–20%) usually confined to pancreatic head and annulus
|
| Rx: |
gastrojejunostomy/duodenojejunostomy |
Ascariasis
| Organism: |
Ascaris lumbricoides, 25–35 cm long as adult worm; life span of 1 year |
| Country: |
644 million humans harbor the roundworm; 70–90% in America; in United States endemic in: Appalachian range, southern + Gulf coast states |
| Prevalence: |
25% of world population infected
(a) in United States: 12% in blacks, 1% in whites
(b) in parts of Africa, Asia, South America: 90% |
Cycle:
ingestion of contaminated water/soil/vegetable; larvae penetrate intestinal wall; migrate into mesenteric lymphatics + veins into liver; reach lung via right heart + pulmonary artery; mature in pulmonary capillary bed to 2–3 mm length; burrow into alveoli; ascend in respiratory tract; are swallowed and again reach small intestine, where they become adult worms whose eggs leave the body by the fecal route
• abnormal liver function tests + biliary colic
• hypereosinophilia only present during acute stage of larval migration
barium study
cholangiography (49%)
-
US:
tubular echogenic filling defect with 2–4-mm wide central sonolucent line (= worm with digestive tract) within dilated common bile duct
| Cx: |
- Intestinal obstruction
- Intermittent biliary obstruction with acute cholangitis, cholecystitis, pancreatitis
- Liver abscess (rare)
- Granulomatous stricture of extrahepatic bile ducts (rare)
|
| Rx: |
Mebendazole |
Autosomal Dominant Polycystic Disease
= POLYCYSTIC LIVER DISEASE
= biliary ductal plate malformation at the level of the small intrahepatic bile ducts with progressive dilation of the abnormal noncommunicating bile ducts of biliary hamartomas
M:F = 1:2
| Associated with: |
polycystic kidney disease (in 50%) |
| Cx: |
infection, compression, bleeding, rupture of cysts |
Banti Syndrome
| Etiology: |
increased portal vascular resistance possibly due to portal fibrosis + obliterative venopathy of intrahepatic portal branches |
| Histo: |
slight portal fibrosis, dilatation of sinusoids, intimal thickening with eccentric sclerosis of peripheral portal vein walls |
| Age: |
middle-aged women; rare in America + Europe but common in India + Japan |
• elevated portal vein pressure (without cirrhosis, parasites, venous occlusion)
• normal liver function tests
• cytopenia (due to hypersplenism)
• normal/slightly elevated hepatic venous wedge pressure
esophageal varices
patent hepatic veins
patent extrahepatic portal vein + multiple collaterals
| Prognosis: |
90% 5-year survival; 55% 30-year survival |
Biliary Cystadenocarcinoma
| Histo: |
(a) with ovarian stroma (good prognosis), in females only
(b) without ovarian stroma (bad prognosis) |
| DDx: |
no image differentiation from biliary cystadenoma |
Biliary Cystadenoma
| Incidence: |
4.6% of all intrahepatic cysts of bile duct origin |
| Age: |
>30 years (82%), peak incidence in 5th decade; M:F = 1:4; predominantly Caucasian |
| Path: |
multilocular cystic tumor containing proteinaceous fluid with well-defined thick capsule |
| Histo: |
single layer of cuboidal/tall columnar biliary-type epithelium with papillary projections, subepithelial stroma resembling that of the ovary
♢ Similar to mucinous cystic tumors of pancreas + ovary |
| Location: |
intrahepatic:extrahepatic bile ducts = 85:15;
right lobe (48%); left lobe (20–35%);
both lobes (15–30%); gallbladder (rare) |
• chronic abdominal pain
• dyspepsia, anorexia, nausea + vomiting
• jaundice
• abdominal swelling with palpable mass (90%)
mass of 1.5–35 cm in size
up to 11 liters of clear/cloudy, serous/mucinous/gelatinous, purulent/hemorrhagic/bilious fluid containing hemosiderin/cholesterol/necrosis
papillary excrescences + mural nodules
septations between cysts
-
US:
ovoid multiloculated anechoic mass with highly echogenic septations/papillary growths
may contain fluid-fluid levels
-
CT:
multiloculated mass of near water density
contrast enhancement in wall + internal septa
-
MR:
locules with variable signal intensity on T1WI + T2WI depending on their protein content
-
Angio:
avascular mass with small clusters of peripheral abnormal vessels
stretching + displacement of vessels
thin subtle blush of neovascularity in septa + wall
| Cx: |
(1) malignant transformation into cystadenocarcinoma (indicated by invasion of capsule)
(2) rupture into peritoneum/retroperitoneum |
| Rx: |
surgical resection (recurrence common) |
| DDx: |
liver abscess, echinococcal cyst, cystic mesenchymal hamartoma (children + young adults), undifferentiated sarcoma (children + young adults), necrotic hepatic metastasis, cystic primary hepatocellular carcinoma |
Biliary-Enteric Fistula
| Incidence: |
5% at cholecystectomy; 0.5% at autopsy |
| Etiology: |
cholelithiasis (90%), acute/chronic cholecystitis, biliary tract carcinoma, regional invasive neoplasm, diverticulitis, inflammatory bowel disease, peptic ulcer disease, echinococcal cyst, trauma, congenital communication |
Communication with:
duodenum (70%), colon (26%), stomach (4%), jejunum, ileum, hepatic artery, portal vein (caused death of Ignatius Loyola), bronchial tree, pericardium, renal pelvis, ureter, urinary bladder, vagina, ovary
-
CHOLECYSTODUODENAL FISTULA (51–80%)
CHOLECYSTOCOLIC FISTULA (13–21%)
-
CHOLEDOCHODUODENAL FISTULA (13–19%)
-
MULTIPLE FISTULAE (7%)
pneumobilia = branching tubular radiolucencies, more prominent centrally within the liver
barium filling of biliary tree
shrunken gallbladder mimicking pseudodiverticulum of duodenal bulb
multiple hyperechoic foci with dirty shadowing
| DDx: |
patulous sphincter of Oddi, ascending cholangitis, surgery (choledochoduodenostomy, cholecystojejunostomy, sphincterotomy) |
Budd-Chiari Syndrome
Cause:
| Pathophysiology: |
hepatic venous thrombosis leads to elevation of sinusoidal pressure, which causes delayed/reversed portal venous inflow, ascites, alteration in hepatic morphology |
| Age: |
all ages; M < F |
right upper quadrant pain
shortness of breath (due to decreased cardiac return)
nonspecific elevated transaminases, jaundice
lower-extremity edema
Location:
| Type I |
: occlusion of IVC ± hepatic veins |
| Type II |
: occlusion of major hepatic veins ± IVC |
| Type III |
: occlusion of small centrilobar veins |
hepatosplenomegaly (early sign)
caudate lobe hypertrophy (88%) [DDx: cirrhosis]
ascites
gallbladder wall thickening >6 mm
nonvisualization of hepatic veins (75%)/vein diameter <3 mm (measured 2 cm from IVC)
communications between right/middle hepatic vein and inferior right hepatic vein
enlarged inferior right hepatic vein (18%)
portal vein diameter >12 mm (in adults), >8 mm (in children)
-
visualization of collateral pathways:
± narrowing/obstruction of intrahepatic IVC
-
NECT:
global liver enlargement + diffuse hypoattenuation
-
CT:
-
“flip-flop” enhancement pattern:
prominent enhancement of central liver + weak enhancement of peripheral liver on early images
enhancement of liver periphery + wash-out of contrast from central liver on delayed images
normal enhancement of enlarged caudate lobe (due to separate venous drainage directly into IVC)
-
mottled liver enhancement pattern (due to hepatic congestion):
patchy liver enhancement (85%) with normal portal blood flow
hypodensity in atrophic areas/periphery (82%) with inversion of portal blood flow (= reversed portal venous blood flow due to increased postsinusoidal pressure produced by hepatic venous obstruction/rarely infarcts)
failure to identify hepatic veins
hepatic vein thrombi (18–53%)
-
MRI:
reduction in caliber/complete absence of hepatic veins
“comma sign” = multiple comma-shaped intrahepatic flow voids (due to intrahepatic collaterals)
-
Doppler US (85–100% sensitive, 85% specific):
one/more major hepatic veins reduced in size to <3 mm/filled with thrombus/not visualized
communicating intrahepatic venous collaterals
decreased/absent/reversed blood flow in hepatic veins
flat flow/loss of cardiac modulation in hepatic veins
demodulated portal venous flow = disappearance of portal vein velocity variations with breathing
slow flow (<11 cm/sec)/hepatofugal flow in portal vein
portal vein congestion index >0.1
portal vein thrombosis (20%)
compression of IVC by enlarged liver/caudate lobe
sluggish/reversed/absent blood flow within IVC
hepatic artery resistive index >0.75
-
NUC (Tc-99m sulfur colloid):
central region of normal activity (hot caudate lobe) surrounded by greatly diminished activity (venous drainage of hypertrophied caudate lobe into IVC by separate vein)
colloid shift to spleen + bone marrow
wedge-shaped focal peripheral defects
-
Angio (inferior venocavography, hepatic venography):
absence of main hepatic veins
spider web pattern of collateral + recanalized veins
high-pressure gradient between infra- and suprahepatic portion of IVC (due to enlarged liver)
stretching + draping of intrahepatic arteries with hepatomegaly
inhomogeneous prolonged intense hepatogram with fine mottling
large lakes of sinusoidal contrast accumulation
-
Portography:
central hepatic enhancement (normal hepatopetal flow)
reversed portal flow in liver periphery (supplied only by hepatic artery)
bidirectional/hepatofugal main portal vein flow
| Dx: |
liver biopsy |
| Rx: |
control of ascites with diuretics + sodium restriction; anticoagulation, thrombolytic therapy, surgery/balloon dilatation (depending on etiology); transjugular portosystemic shunt; orthotopic liver transplantation (for advanced cases) |
Acute Budd-Chiari Syndrome (1/3)
Chronic Budd-Chiari Syndrome (2/3)
• insidious onset of jaundice, intractable ascites
• portal hypertension, variceal bleeding
enlargement of central region (= caudate lobe + adjacent central part of right lobe + medial segment of left lobe
nonsegmental/lobar atrophy of affected liver (due to extensive fibrosis) with diminished attenuation before + after contrast administration
progressive patchy enhancement radiating outward from major portal vessels (on dynamic bolus CT)
“reticulated mosaic” enhancement = diffuse patchy lobular enhancement separated by irregular linear areas of low density in central area
delayed homogeneous enhancement of entire liver after several minutes
ascites
-
Color Doppler:
“bicolored” hepatic veins (due to intrahepatic collateral pathways) are PATHOGNOMONIC
-
MR:
absence of flow within hepatic veins
minimal differences in signal intensity between central and peripheral portions of liver
intrahepatic collateral vessels
Candidiasis Of Liver
= almost exclusively seen in immunocompromised patients (acute leukemia, chronic granulomatous disease of childhood, renal transplant, chemotherapy for myeloproliferative disorders)
| Prevalence: |
at time of autopsy in 50–70% of acute leukemia, in 50% of lymphoma patients
♢ Most common systemic fungal infection in immunocompromised patients! |
| Dx: |
biopsy evidence of yeast/pseudohyphae in central necrotic portion of lesion |
| DDx: |
metastases, lymphoma, leukemia, sarcoidosis, septic emboli, other infections (MAI, CMV), Kaposi sarcoma |
Caroli Disease
[Jacques Caroli (1902–1979), surgeon in Paris, France]
COMMUNICATING CAVERNOUS ECTASIA OF INTRAHEPATIC DUCTS
rare congenital probably autosomal recessive disorder characterized by multifocal segmental saccular cystic dilatation of the large intrahepatic bile ducts, which retain their communication with the biliary tree
| Etiology: |
(a)? perinatal hepatic artery occlusion
(b)? hypoplasia/aplasia of fibromuscular wall components |
| Age: |
childhood + 2nd–3rd decade, occasionally in infancy; M:F = 1:1 |
| Associated with: |
benign renal tubular ectasia, medullary sponge kidney (in 80%), infantile polycystic kidney disease, choledochal cyst (rare), congenital hepatic fibrosis |
• recurrent cramplike upper abdominal pain
• fever, transient jaundice
• cirrhosis/portal hypertension (very rare)
multiple cystic structures converging toward porta hepatis as either localized/diffusely scattered cysts communicating with bile ducts (DDx: polycystic liver disease)
sludge/calculi in dilated ducts
-
CT/US/ MR:
central dot sign = portal vein radicles completely surrounded by dilated bile ducts
-
Cholangiography (diagnostic):
segmental saccular/fusiform/beaded dilatation of intrahepatic bile ducts extending to periphery of liver up to 5 cm in diameter
bridge formation across dilated lumina
intraluminal bulbar protrusions
frequent ectasia of extrahepatic ducts + CBD
| Cx: |
(1) Bile stasis with recurrent cholangitis
(2) Biliary calculi (predominantly bilirubin)
(3) Liver abscess
(4) Septicemia
(5) Increased risk for cholangiocarcinoma (7%) |
| DDx: |
polycystic liver disease (noncommunicating), biliary hamartoma (noncommunicating); primary sclerosing cholangitis, recurrent pyogenic cholangitis |
Cholangiocarcinoma
| Incidence: |
0.5–1% of all cancers, 30% of hepatic primary malignancies
♢ Cholangiocarcinomas occur in 10–15% of patients with primary sclerosing cholangitis! |
Location:
-
INTRAHEPATIC
-
EXTRAHEPATIC
| common hepatic duct |
in |
14–37% |
| proximal CBD |
in |
15–30% |
| distal CBD |
in |
30–50% |
| cystic duct |
in |
6% |
Path:
-
exophytic (= mass-forming/nodular) type:
-
diffuse = infiltrative (periductal) type:
-
polypoid = papillary (intraductal) type: infrequent
intraluminal polypoid mass
combination
| Histo: |
well/moderately/poorly differentiated ductal (most common), papillary, mucinous, signet-ring cell, mucoepidermoid, adenosquamous, cystadenocarcinoma Unusual manifestation:
- Mucin-hypersecreting cholangiocarcinoma
√severe diffuse dilatation of intra- and extrahepatic bile ducts proximal + distal to tumor - Squamous cell carcinoma
= metaplastic transformation of adenocarcinoma cells
|
Predisposed:
Inflammatory bowel disease (10 × increased risk); incidence of 0.4–1.4% in ulcerative colitis; latent period of 15 years; tumors usually multicentric + predominantly in extrahepatic sites; GB involved in 15% (simultaneous presence of gallstones is rare)
Biliary lithiasis: cholecystolithiasis (20–50%), intrahepatic lithiasis (5–10%)
Primary sclerosing cholangitis (10%)
Clonorchis sinensis infestation (Far East); most common cause worldwide
Choledochal cyst/congenital hepatic cyst/congenital biliary atresia
-
Ductal plate malformation:
Biliary hamartoma
Autosomal dominant polycystic disease
Congenital hepatic fibrosis
Caroli disease (due to chronic biliary stasis)
Papillomatosis of bile ducts
Recurrent pyogenic cholangitis
Choledochoenteric anastomosis
History of other malignancy (10%)
Thorotrast exposure
Alpha–1 antitrypsin deficiency
| Prognosis: |
median survival of 7 months, 0–10% 5-year survival |
Intrahepatic Cholangiocarcinoma
| Incidence: |
1/3 of all malignancies originating in the liver; 8–13% of all cholangiocarcinomas; 2nd most common primary hepatic tumor after hepatoma |
| Histo: |
adenocarcinoma arising from the epithelium of a small intrahepatic bile duct with prominent desmoplastic reaction (fibrosis); ± mucin and calcifications |
| Average age: |
50–60 years; M > F |
| Spread: |
(a) local extension along duct
(b) local infiltration of liver substance
(c) metastatic spread to regional lymph nodes (in 15%) |
mass of 5–20 cm in diameter
satellite nodules in 65%
punctate/chunky calcifications in 18%
calculi in biliary tree
-
NUC:
cold lesion on sulfur colloid/IDA scans
segmental biliary obstruction
may show uptake on gallium scan
-
US:
dilated biliary tree
predominantly homo-/heterogeneous mass
hyper- (75%)/iso-/hypoechoic (14%) mass
mural thickening
-
CT:
single predominantly homogeneous round/oval hypodense mass with irregular borders
“peripheral washout sign” = early minimal/moderate rim enhancement with progressive concentric filling and clearing of contrast material in rim of lesion on delayed images
marked homogeneous delayed enhancement (74%)
-
MR:
large central heterogeneous hypointense mass on T1WI
hyperintense periphery (viable tumor) + large central hypointensity (fibrosis) on T2WI
gadolinium enhancement of lesion
-
Angiography:
avascular/hypo-/hypervascular mass
stretched/encased arteries (frequent)
neovascularity in 50%
lack of venous invasion
| Prognosis: |
<20% resectable; 30% 5-year survival |
Klatskin Tumor
[Gerald Klatskin (1910–1986), pathologist in yale, USA]
= INTRAhEPATIC CENTRAL ChoLANGIoCARCINoMA
= tumor at confluence of hepatic ducts (up to 70% of cholangiocarcinomas)
-
direct signs of Klatskin tumor:
iso- to hyperechoic central porta hepatis mass/focal irregularity of ducts (for infiltrating cholangiocarcinoma = more common subtype)
polypoid/smooth nodular intraluminal mass (for papillary + nodular types of cholangiocarcinoma) with associated mural thickening
-
indirect signs of Klatskin tumor:
segmental dilatation with nonunion of right and left ducts at porta hepatis + normal caliber of extrahepatic ducts
pressure effect/encasement/invasion/obliteration of portal vein and hepatic artery
lobar atrophy (14%) = dilated crowded ducts extending to liver surface ± geographic fatty change in one lobe
Intrahepatic Peripheral Cholangiocarcinoma
| Location: |
right lobe predilection |
solitary mass (nodular form) without hypoechoic halo
-
diffusely abnormal liver texture (infiltrative form):
tumor more hypoechoic if <3 cm
tumor more hyperechoic if >3 cm
well-marginated cystic mass (papillary mucinproducing tumor) ± diffuse hyperechoic flecks of tumor calcification
dilatation of bile ducts peripheral to tumor (31%)
| DDx: |
metastatic adenocarcinoma/leiomyosarcoma; sclerosing hepatocellular carcinoma |
Extrahepatic Cholangiocarcinoma
| Age peak: |
6th–7th decade, M:F = 3:2 |
| Incidence: |
<0.5% of autopsies; 90% of all cholangiocarcinomas; more frequent in Far East |
| Histo: |
well-differentiated sclerosing adenocarcinoma (2/3), anaplastic carcinoma (11%), cystadenocarcinoma, adenoacanthoma, malignant adenoma, squamous cell = epidermoid carcinoma, leiomyosarcoma |
gradual onset of fluctuating painless jaundice
cholangitis (10%)
weight loss, fatigability
intermittent epigastric pain
elevated bilirubin + alkaline phosphatase
enlarged tender liver
-
Growth pattern:
| Spread: |
(a) lymphatic spread: cystic + CBD nodes (>32%), celiac nodes (>16%), peripancreatic nodes, superior mesenteric nodes
(b) infiltration of liver (23%)
(c) peritoneal seeding (9%)
(d) hematogenous (extremely rare): liver, peritoneum, lung |
-
UGI:
infiltration/indentation of stomach/duodenum Cholangiography (PTC or ERC best modality to depict bile duct neoplasm):
exophytic intraductal tumor mass (46%), 2–5 mm in diameter
frequently long/rarely short concentric focal stricture in infiltrating sclerosing cholangitic type with wall irregularities
prestenotic diffuse/focal biliary dilatation (100%)
progression of ductal strictures (100%)
-
US/CT:
dilatation of intrahepatic ducts without extrahepatic duct dilatation
failure to demonstrate the confluence of L + R hepatic ducts
mass within/surrounding the ducts at point of obstruction (21% visible on US, 40% visible on CT)
infiltrating tumor visible as highly attenuating lesion in 22% on CT, in 13% on US
exophytic tumor visible in 100% on CT as low-attenuation mass, in 29% on US
polypoid intraluminal tumor visible as isoechoic mass within surrounding bile in 100% on US, in 25% on CT
-
CECT:
hyperattenuating lesion at delayed imaging (due to delayed accumulation + washout of fibrous center)
-
Angiography:
hypervascular tumor with neovascularity (50%)
arterioarterial collaterals along the course of bile ducts associated with arterial obstruction
poor/absent tumor stain
displacement/encasement/occlusion of hepatic artery + portal vein
| Cx: |
(1) Obstruction leading to biliary cirrhosis
(2) Hepatomegaly
(3) Intrahepatic abscess (subdiaphragmatic, perihepatic, septicemia)
(4) Biliary peritonitis
(5) Portal vein invasion |
| Dx: |
endoscopic brush biopsy (30–85% sensitive) |
| Prognosis: |
median survival of 5 months; 1.6% 5-year survival; 39% 5-year survival for carcinoma of papilla of Vater |
| DDx: |
sclerosing cholangitis, AIDS cholangitis, benign stricture, chronic pancreatitis, edematous papilla, idiopathic inflammation of CBD |
Cholangitis
Acute Obstructive/Ascending Cholangitis
Cause:
-
benign disease:
-
malignant disease:
Types:
• recurrent episodes of sepsis + RUQ pain
• Charcot triad (70%): fever + chills + jaundice
• bile cultures in 90% positive for infection
may have gas in biliary tree
-
CECT:
| Cx: |
miliary hepatic abscess formation; secondary sclerosing cholangitis |
AIDS-related Cholangitis
| Organism: |
Cryptosporidium (protozoan parasite typically infecting GI tract epithelium), CMV |
| Histo: |
marked periductal inflammatory response with interstitial edema + interstitial inflammatory cell infiltrates + necrotic biliary epithelium |
• RUQ pain, fever, nausea, jaundice
• elevated WBC count
• abnormal LFTs (esp. serum alkaline phosphatase)
• opportunistic organism isolated from bile (in 50%)
irregular mild dilatation of intra- and extrahepatic bile ducts resembling sclerosing cholangitis
-
US:
stricture of distal CBD/papillary stenosis (due to papillitis)
echogenic nodule at the distal end of the CBD
mural thickening of gallbladder + bile ducts
periductal echogenicity
± pericholecystic fluid
-
CT:
“pseudogallstone” appearance = marked circumferential edema of gallbladder wall + mucosal enhancement
periportal edema
-
Cholangiography:
strictures + beading of central intrahepatic bile ducts
pruning of peripheral bile ducts
| DDx: |
acalculous cholecystitis, papillary stenosis, sclerosing cholangitis |
Chemotherapy-induced Cholangitis
| Predisposed: |
patients with liver metastases from colon cancer |
| Cause: |
direct effect of hepatic arterial infusion with chemotherapeutic agents (eg, floxuridine)/ischemia secondary to thrombosis of intrahepatic arterial branches |
bile duct strictures as early as 2 months after therapy (in up to 15%)
stricture of common hepatic duct + sparing of distal CBD
Primary Sclerosing Cholangitis
= insidious progressive obliterative fibrosing inflammation of the biliary tree causing multifocal strictures, bile duct obliteration, cholestasis, and biliary cirrhosis
| Etiology: |
idiopathic,? autoimmune process (speculative); altered bile acid metabolism with increase in lithocholic acid by bacterial overgrowth |
| Prevalence: |
1% as common as alcoholic liver disease |
| Age: |
<45 years (2/3); mean 39 (range 21–67) years;M:F = 7:3 |
Histo:
| Stage 1: |
degeneration of epithelial bile duct cells + infiltration with lymphocytes ± neutrophils; inflammation + scarring + enlargement of periportal triads (pericholangitis) |
| Stage 2: |
fibrosis + inflammation infiltrating periportal parenchyma with piecemeal necrosis of hepatocytes; enlargement of portal triads; bile ductopenia |
| Stage 3: |
portal-to-portal fibrous septa; severe degenerative changes + disappearance of bile ducts; cholestasis in periportal + paraseptal hepatocytes |
| Stage 4: |
frank cirrhosis |
Associated with:
-
Inflammatory bowel disease (ulcerative colitis in 50–74%, Crohn disease in 13%)
1–4% of patients with inflammatory bowel disease develop secondary sclerosing cholangitis!
10% of patients with primary sclerosing cholangitis have Crohn disease
Cirrhosis, chronic active hepatitis, pericholangitis, fatty degeneration
Pancreatitis
Retroperitoneal/mediastinal fibrosis
Peyronie disease
Riedel thyroiditis, hypothyroidism
Retroorbital pseudotumor
Sjögren syndrome
abnormal liver function tests: serum bilirubin, serum alkaline phosphatase, γ-glutamyltransferase
progressive chronic/intermittent obstructive jaundice (75%)
history of previous biliary surgery (53%) + chronic/recurrent pancreatitis (14%)
fever, night sweats, chills, RUQ pain, pruritus (10–15%)
-
Location:
CBD almost always involved
Intra- and extrahepatic ducts (68–89%)
Cystic duct involved in 15–18%
Intrahepatic ducts only (1–11–25%)
Extrahepatic ducts only (2–3%)
intrahepatic bile duct calculi (8–30%): soft black crushable stones/sandlike grit
-
US:
brightly echogenic portal triads
echogenic biliary casts/punctate coarse calcifications along portal vein branches
± gallbladder wall thickening
-
CT:
dilatation, stenosis, pruning (decreased arborization), beading of tortuous intrahepatic bile ducts = “tree-in-winter” appearance (80%)
wall nodularity, duct wall thickening, mural contrast enhancement of extrahepatic bile ducts (100%)
hepatic metastases + lymph nodes in porta hepatis
subtle foci of high attenuation in intrahepatic bile ducts
lobar atrophy in preferentially affected portions
-
Cholangiography:
-
multifocal strictures with predilection for bifurcations + skip lesions (uninvolved duct segments of normal caliber) involving intra- and extrahepatic bile ducts:
-
CLASSIC “string-of-beads” appearance
“pruned tree” appearance (= opacification of central ducts + nonvisualization of peripheral smaller radicles due to diffuse obstruction)
“cobblestone” appearance (= coarse nodular mural irregularities) in 50%
new strictures + lengthening of strictures between 6 months and 6 years (<20%)
minimal duct dilatation due to periductal inflammation + fibrosis
-
marked ductal dilatation (24%)
| DDx: |
ascending cholangitis, cholangiocarcinoma |
small eccentric saccular outpouchings (diverticula/pseudodiverticula) [up to 27%] = PATHOGNOMONIC
webs = focal 1–2-mm-thick areas of incomplete circumferential narrowing
angles formed between central and peripheral ducts change from acute to obtuse
polypoid mass (7%)
gallbladder irregularities uncommon
-
MR:
periportal intermediate intensity on T1WI + hyperintense on T2WI (due to inflammation)
-
NUC (Tc-99m-IDA scan):
multiple persistent focal areas of retention in distribution of intrahepatic biliary tree
marked prolongation of hepatic clearance
gallbladder visualized only in 70%
| Cx: |
(1) Biliary cirrhosis (up to 49%)
(2) Portal hypertension
(3) Cholangiocarcinoma (clinically in 4–19%; in 7–36% at autopsy/liver transplantation)
(4) Secondary cholangitis |
| Rx: |
(1) Palliative: ursodeoxycholic acid, dilatation of dominant strictures
(2) Curative: liver transplantation (4th leading indication) |
| DDx: |
(1) Sclerosing cholangiocarcinoma (progressive cholangiographic changes within 0.5–1.5 years of initial diagnosis, marked ductal dilatation upstream from a dominant stricture, intraductal mass >1 cm in diameter)
(2) Acute ascending cholangitis (history)
(3) Primary biliary cirrhosis (disease limited to intrahepatic ducts, strictures less pronounced, pruning + crowding of bile ducts, normal AMA titer)
(4) AIDS cholangiopathy (same on cholangiography) |
Recurrent Pyogenic Cholangitis
= PRIMARY CHOLANGITIS = RECURRENT PYOGENIC HEPATITIS/CHOLANGITIS = ORIENTAL CHOLANGIO-HEPATITIS = ORIENTAL CHOLANGITIS = HONG KONG DISEASE = INTRAHEPATIC PIGMENT STONE DISEASE
= chronic recurrent parasitic cholangitis resulting in progressive destructive cholangiopathy + liver failure
| Etiology: |
? Clonorchis sinensis infestation, coliform infection of bile, portal bacteremia, malnutrition |
| Incidence: |
3rd most common cause of an acute abdomen in Hong Kong after appendicitis and perforated ulcer; uncommon in United States |
| Epidemiology: |
endemic to Southeast Asia (South China, Indochina, Taiwan, Japan, Korea); Asian immigrants in United States |
Associated intrabiliary infestation:
| Path: |
pericholangitis, periductal abscesses, fibrosis of bile duct walls, heavy infiltration of portal tracts by PMNs, intraductal bile pigment calculi |
| Age: |
20–50 years; M:F = 1:1 |
| Location: |
particularly in lateral segment of L lobe + posterior segment of R lobe |
marked dilatation of proximal intrahepatic ducts (3–4 mm) in 100%
decreased arborization of intrahepatic radicles
intra- and extrahepatic bile ducts filled with nonshadowing soft mudlike pigment (= calcium bilirubinate) stones (74%)
dilatation of CBD (68%) + choledocholithiasis (30%)
multifocal bile duct strictures (22%)
pneumobilia (3–52%)
biloma
segmental hepatic atrophy (36%)
hepatic abscesses
-
CT:
high-attenuation biliary calculi
enhancement of bile duct wall
-
Associated findings:
gallstones
splenomegaly
varices
-
ERCP:
Worsening of cholangitis/sepsis if patients do not receive antibiotics!
acute tapering + straightening + rigidity of bile ducts
decreased arborization + increased branching angle of bile ducts
| Cx: |
liver abscess (18%), splenomegaly (14%), biloma (4%), pancreatitis (4%), cholangiocarcinoma (2.5–6%) |
| Rx: |
endoscopic sphincterotomy, choledochoduodenostomy |
| DDx: |
(1) Caroli disease (saccular dilatation of intrahepatic bile ducts)
(2) Primary sclerosing cholangitis (focal discontinuous bile duct dilatation)
(3) Clonorchiasis (biliary ductal dilatation limited to intrahepatic bile ducts) |
Secondary Sclerosing Cholangitis
Cause:
Chronic bacterial cholangitis from bile duct stricture/choledocholithiasis
Ischemic bile duct damage from treatment with floxuridine
Infectious cholangiopathy in AIDS
Previous biliary tract surgery
Congenital biliary tree anomalies
Bile duct neoplasm
Cholecystitis
Acute Calculous Cholecystitis
| Etiology: |
(a) in 80–95% cystic duct obstruction by impacted calculus; 85% disimpact spontaneously if stone <3 mm
(b) in 10% acalculous cholecystitis |
| Pathogenesis: |
chemical irritation from concentrated bile, bacterial infection, reflux of pancreatic secretions |
| Age peak: |
5th–6th decade; M:F = 1:3 |
| Associated with: |
choledocholithiasis (15–25%) |
persisting (>6 hours) RUQ pain radiating to right shoulder/scapula/interscapular area (DDx: biliary colic usually <6 hours)
nausea, vomiting, chills, fever
RUQ tenderness + guarding
± leukocytosis, elevated levels of alkaline phosphatase and transaminase and amylase
mild hyperbilirubinemia (20%)
Murphy sign = inspiratory arrest upon palpation of GB area (falsely positive in 6% of patients with cholelithiasis)
Oral cholecystography:
nonvisualization/poor visualization of gallbladder
US (81ndash; 100% sensitivity, 60–100% specificity, 92% PPV, 95% NPV):
-
± GB wall thickening >3 mm (45–72% sensitive, 76–88% specific):
hazy delineation of GB wall
“halo sign” = GB wall lucency (in 8%) = 3-layered configuration with sonolucent middle layer (edema)
striated wall thickening (62%) = several alternating irregular discontinuous lucent + echogenic bands within GB wall (100% PPV)
GB hydrops = distension with AP diameter >5 cm or enlargement of greater than 4 × 10 cm
-
positive sonographic Murphy sign (in 85–88%)
= maximum tenderness during compression with transducer directly over gallbladder (63–94% sensitive, 85–93% specific, 72% NPV)
-
False-negative sonographic Murphy sign:
lack of patient responsiveness, pain medication, inability to press directly on GB (position deep to liver/protected by ribs), GB wall necrosis
-
crescent-shaped/loculated pericholecystic fluid (in 20%)
-
gallstones (83–98% sensitive, 52–77% specific):
impacted gallstone in GB neck/cystic duct
-
echogenic shadowing fat within hepatoduodenal ligament ± conspicuous color Doppler flow (due to inflammation)
sludge
Color Doppler US:
visualization of cystic artery >50% of the length of the gallbladder (30% sensitive, 98% specific)
CECT:
distended gallbladder
gallbladder wall thickness >3 mm
increased gallbladder wall attenuation
transient focal increased attenuation around gallbladder fossa on hepatic arterial phase (due to hepatic arterial hyperemia + early venous drainage)
haziness of pericholecystic fat
pericholecystic fluid
increased attenuation of bile
NUC (86–97% sensitivity, 73–100% specificity, 95–98% accuracy):
Endpoint of imaging:
False-positive scans (10–12%) = nonvisualization of GB without acute cholecystitis:
prolonged fasting, total parenteral nutrition, hyperalimentation, recent feeding <4–6 hours prior to study, severe intercurrent illness, CBD obstruction, congenital absence of GB, post-cholecystectomy, carcinoma of GB, chronic cholecystitis, acute pancreatitis, alcoholic liver disease, hepatocellular disease
-
Reduction to 2% false-positive scans through:
delayed images up to 4 hours
cholecystokinin (Sincalide®) injection 15 minutes prior to study
morphine IV (0.04 mg/kg) at 40 minutes + reimaging after 20 minutes (contraction of sphincter of Oddi + rise in intrabiliary pressure)
False-negative scans (4.8%) = visualization of GB despite acute cholecystitis:
Cholangiography:
sharply defined filling defect in contrast-material filled lumen of cystic duct
MR cholangiopancreatogram (high sensitivity):
low-signal–intensity defect surrounded by high-signal–intensity bile on T2WI
Cx:
Gangrene
Abscess (pericholecystic)
Mirizzi syndrome
Emphysematous cholecystitis
Bouveret syndrome (= gallstone erodes into duodenum leading to duodenal obstruction)
Empyema
Gallstone ileus
GANGRENE OF GALLBLADDER
Pericholecystic Abscess
| Cause: |
subacute perforation of gallbladder wall subsequent to gangrene + infarction due to acute cholecystitis |
| Prevalence: |
2–20% |
Location:
Rx:
Perforation of Gallbladder (in 2–20%)
-
Types:
Acute free perforation with peritonitis causing pericholecystic abscess in 33%
Subacute localized perforation causing pericholecystic abscess in 48%
Chronic perforation resulting in internal biliary fistula causing pericholecystic abscess in 18%
| Location: |
most commonly at fundus |
gallstone lying free in peritoneal cavity
sonolucent/complex collection surrounding GB
collection in liver adjacent to gallbladder
Empyema of Gallbladder
multiple medium/coarse highly reflective intraluminal echoes without shadowing/layering/gravity dependence (purulent exudate/debris)
Acute Acalculous Cholecystitis
| Frequency: |
5–15% of all acute cholecystitis cases |
| Associated with: |
recent surgery in 50% |
| Etiology: |
probably caused by decreased blood flow within cystic artery |
-
debilitated patients: depressed motility/starvation in trauma, burns, surgery, total parenteral nutrition, anesthesia, positive pressure ventilation, narcotics, shock, vasoactive amines, congestive heart failure, arteriosclerosis, polyarteritis nodosa, SLE, diabetes mellitus
Diagnosis in the ICU patient sonographically difficult due to fasting state, medications, CHF, etc.
obstruction of cystic duct by extrinsic inflammation, lymphadenopathy, metastases
infection (only in 50%) from Salmonella, Helicobacter, cholera, Kawasaki syndrome, cytomegalovirus, cryptosporidiosis
thickened gallbladder wall >4–5 mm
echogenic bile/sludge
gallbladder distension
pericholecystic fluid in absence of ascites
striated subserosal edema
sloughed mucosal membrane
Murphy sign = pain + tenderness with transducer pressure over the gallbladder (difficult to assess in ICU patient with altered mental status)
decreased response to cholecystokinin
intramural gas
-
CT:
pericholecystic stranding (= edema)
decreased attenuation in adjacent liver (= perihepatitis)
| NUC: |
same criteria as for calculous cholecystitis |
| Cx: |
gallbladder perforation, gangrene, pericholecystic abscess |
| Rx: |
percutaneous cholecystostomy trial (low threshold for ICU patients) |
| Prognosis: |
6.5% mortality rate |
Chronic Cholecystitis
Most common form of gallbladder inflammation
gallstones
smooth/irregular GB wall thickening (mean of 5 mm)
mean volume of 42 mL
-
NUC:
normal GB visualization in majority of patients
delayed GB visualization (1–4 hours)
visualization of bowel prior to GB (sensitivity 45%, specificity 90%)
noncontractility/decreased response after CCK injection (decreased GB ejection fraction)
Emphysematous Cholecystitis
| Etiology: |
small-vessel disease with cystic artery occlusion, complication of acute cholecystitis |
| Organism: |
Clostridium perfringens, Clostridium welchii, E. coli, staphylococcus, streptococcus |
| Age: |
>50 years; M:F = 5:1 |
| Predisposed: |
diabetics (20–50%), debilitating diseases; calculous (70–80%)/acalculous cystic duct obstruction |
| Cx: |
gangrene (75%); gallbladder perforation (20%) |
| Mortality: |
15% |
| DDx: |
(1) Enteric fistula
(2) Incompetent sphincter of Oddi
(3) Air-containing periduodenal abscess
(4) Periappendiceal abscess in malpositioned appendix
(5) Lipomatosis of gallbladder |
Xanthogranulomatous Cholecystitis
| Incidence: |
1–2% |
| Age: |
7th + 8th decade |
| Histo: |
mixture of ceroid (waxlike) xanthogranuloma with foamy histiocytes + multinucleated foreign body giant cells + lymphocytes + fibroblasts containing areas of necrosis (in newer lesions) |
| May be associated with: |
gallbladder carcinoma (11%) |
preservation of 2–3-mm thick mucosal lining (in 82%)
thickened gallbladder wall: 91% diffuse, 9% focal
infiltration of pericholecystic fat: in 45% focal, in 54% diffuse
hepatic extension (45%)
biliary obstruction (36%)
lymphadenopathy (36%)
-
US:
intramural hypoechoic nodules
-
CT:
5–20-mm small intramural hypoattenuating nodules
poor/heterogeneous contrast enhancement
| DDx: |
gallbladder carcinoma (in 59% focal, in 41% diffuse thickening of gallbladder wall, multiple masses within liver) |
 |
| Choledochal Cysts |
Choledochal Cyst
| Etiology: |
anomalous junction of pancreatic duct and CBD proximal to duodenal papilla; higher pressure in pancreatic duct and absent ductal sphincter allows free reflux of enzymes into CBD resulting in weakening of CBD wall |
Classification:
| Kimura type I |
= pancreatic duct enters the proximal/mid CBD (10–58%) at right angle |
| Kimura type II |
= CBD drains into pancreatic duct |
| Prevalence: |
1:13,000 admissions; high prevalence in Japanese/Asian infants |
| Age: |
<10 years (60%) + young adulthood; 80% diagnosed in childhood; 7% during pregnancy; occasionally detected up to 8th decade; M:F = 1:4 |
| Histo: |
fibrous cyst wall without epithelial lining |
Associated with:
dilatation, stenosis or atresia of other portions of the biliary tree (2%)
gallbladder anomaly (aplasia, double GB)
failure of union of left + right hepatic ducts
pancreatic duct + accessory hepatic bile ducts may drain into cyst
polycystic liver disease
-
• Classic triad (20–30% of adult patients):
-
intermittent obstructive jaundice (33–50%)
Uncommon cause of obstructive jaundice!
recurrent RUQ colicky pain (>75–90%), back pain
intermittent palpable RUQ abdominal mass (<25%)
• recurrent fever, chills, weight loss, pruritus
| Cx: |
(1) Stones in gallbladder, in CBD, within cyst, in intrahepatic biliary tree, in pancreatic duct (8–50%)
(2) Malignant transformation into bile duct carcinoma + gallbladder carcinoma (increasing with age, <1% in 1st decade, 7–14% >age 20)
(3) Recurrent pancreatitis (33%)
(4) Cholangitis/cholecystitis (20%)
(5) Cyst rupture with bile peritonitis (1.8
%) (6) Bleeding
(7) Biliary cirrhosis + portal hypertension
(8) Portal vein thrombosis
(9) hepatic abscess |
| Rx: |
excision of cyst + Roux-en-Y hepaticojejunostomy |
| DDx: |
mesenteric, omental, ovarian, renal, adrenal, hepatic, enteric duplication cyst, pancreatic pseudocyst, hydronephrotic kidney, hepatic artery aneurysm, biloma (from spontaneous perforation of CBD) |
Choledochocele
= DUODENAL DUPLICATION CYST = ENTEROGENOUS CYST OF AMPULLA OF VATER/DUODENUM = INTRADUODENAL CHOLEDOCHAL CYST = DIVERTICULUM OF COMMON BILE DUCT
= cystic dilatation of the distal/intramural duodenal portion of the CBD with herniation of CBD into duodenum (similar to ureterocele)
-
Etiology:
| Age: |
33 years (manifestation usually in adulthood) |
| Types: |
(a) CBD terminates in cyst, cyst drains into duodenum (common)
(b) cyst drains into adjacent intramural portion of CBD (less common) |
| Associated with: |
stones/sludge (frequent) |
| Cx: |
pancreatitis, duodenal obstruction |
| Rx: |
sphincterotomy/sphincteroplasty |
| DDx: |
choledochal cyst (involves more than only terminal portion of CBD) |
Cholelithiasis
Prevalence:
25 million adults in United States; 10% of population + 2% of children;
increasing with age (40% of women in 9th decade);
in 3rd decade M:F = 2%:4%
in 7th decade M:F = 10%:25%
| Predisposing factors: |
“female, forty, fair, fat, fertile, flatulent” |
Pathogenesis:
supersaturation of bile constituents, most notably cholesterol, related to defects in biliary lipid metabolism; biliary dysmotility; prolonged intestinal transit; aggravated by sedentary lifestyle + diet
Composition:
Radiopacity:
-
lucent stones (84%):
-
calcified stones (15–20% on plain film, 60% on CT):
-
Location of calcium:
calcium phosphate deposited centrally within cholesterol stones
calcium carbonate deposited radially within aging cholesterol/peripherally around cholesterol + pigmented stones
Gallstones in Fetus
| EGA: |
>28 weeks EGA |
| Cause: |
hemolytic disease, cholestasis, maternal drug use |
| Prognosis: |
usually resolve before/after delivery |
Gallstones in Neonate
Rare without predisposing factors
| Associated with: |
obstructive congenital biliary anomaly, total parenteral nutrition, furosemide, GI dysfunction (short-gut syndrome), prolonged fasting, phototherapy, dehydration, infection, hemolytic anemia |
Gallstones in Older Children
| Associated with: |
sickle cell disease, cystic fibrosis, malabsorption, total parenteral nutrition, Crohn disease, intestinal resection, hemolytic anemia, choledochal cyst |
Cholecystolithiasis
• asymptomatic (60–65%); become symptomatic at a rate of 2% per year
-
• biliary colic (misnomer) due to transient obstruction of cystic duct/common bile duct develops in 33% (18% overall risk in 20 years):
-
Abdominal plain film (10–16% sensitive):
calcified gallstones
-
OCG (65–90% sensitive):
-
filling defect in contrasted gallbladder lumen:
allows determination of size + number of gallstones
demonstrates cystic duct patency
shows contractility after a fatty meal
nonvisualization of gallbladder (25%) = inconclusive
-
CT (80% sensitive):
hyperdense calcified gallstones in 60%
-
hypodense cholesterol stones ≤140 HU = pure cholesterol stone (= ≥80% cholesterol content):
Inverse relationship between CT attenuation number + cholesterol content
gallstones isointense to bile in 21–24% and thus undetectable by CT (<30 HU)
-
US (91–98% sensitive; in 5% falsely negative):
-
bright (= highly reflective) echo from anterior surface of gallstone within gallbladder:
marked posterior acoustic shadowing
mobile upon repositioning of patient (may infrequently be adherent to wall)
reverberation artifact
Small calcifications <2 mm may not shadow
-
nonvisualization of GB + collection of echogenic echoes with acoustic shadowing (15–25%):
“wall-echo-shadow” = “double-arc shadow” sign = 2 echogenic curvilinear parallel lines separated by sonolucent line (ie, anterior GB wall + bile + stone with acoustic shadowing)
focal nonshadowing opacities <5 mm in diameter (in 70% gallstones)
-
False-negative US (5%):
contracted GB, GB in anomalous/unusual location, small gallstone, gallstone impacted in GB neck/cystic duct, immobile patient, obese patient, extensive RUQ bowel gas
| Prognosis: |
stones <3 mm may pass through cystic duct |
| Cx: |
acute cholecystitis (in 30%), choledocholithiasis, cholangitis, pancreatitis, duodenitis, biliary fistula, gallstone ileus, Mirizzi syndrome; cancer of GB + bile ducts (2–3 × more frequent) |
Cholangiolithiasis
Choledocholithiasis
Most common cause of bile duct obstruction!
| Etiology: |
(a) passed stones originating in GB
(b) primary development in intra-/extrahepatic ducts |
| Incidence: |
in 12–15% of cholecystectomy patients; in 3–4% of postcholecystectomy patients; in 75% of patients with chronic bile duct obstruction |
-
Risk indicators for CBD stone:
recent history of jaundice
recent history of pancreatitis
elevated serum bilirubin >17 μmol/L
elevated serum amylase >120 IU/L
dilated CBD >6 mm (16%)
obscured bile duct
• asymptomatic: 10% of patients treated with cholecystectomy have unsuspected CBD calculi
• recurrent episodes of right upper quadrant pain, jaundice, chills, fever (25–50%)
• elevated serum bilirubin + alkaline phosphate levels
• elevated transaminase (75%)
• spontaneous passage with stones <6 mm size
-
Cholangiography (most specific technique):
stone visualization in 92%
dependent round filling defects
| DDx: |
air bubbles, neoplasm, concentrated bile |
-
US (22–82% sensitive):
stone visualization in 13–75% (more readily with CBD dilatation + good visibility of pancreatic head)
dilated ducts in 64–77%/duct <8 mm in diameter in 24–36%
increased dilatation of CBD with administration of fatty meal/cholecystokinin
no stone in gallbladder (1.2–11%)
-
CT (88% sensitive, 97% specific, 94% accurate):
stone visualization in 75–88% (isoattenuating to bile in 12–25%)
target sign = intraluminal mass with crescentic ring (= stone of soft-tissue density) in 85%
subtle alternating low- and high-attenuation rings (= mixed cholesterol-calcium stones)
-
MRCP (81–100% sensitive, 85–100% specific):
dark filling defect within hyperintense fluid (stone must be >2 mm in diameter) (DDx: tumor, edematous papilla of Vater
signal void on moderately T2WI (TE of 100 msec) BUT tumors have intermediate signal intensity
no enhancement of calculus
-
obscured/missed calculi:
visible signal intensity on T1WI due to sufficient water content
isointensity relative to bile
-
NUC:
delayed bowel activity beyond 2 hours
persistent hepatic + common bile duct activity to 24 hours
prominent ductal activity beyond 90 minutes with visualization of secondary ducts
Stone in Cystic Duct Remnant
Chronic Granulomatous Disease Of Childhood
| Etiology: |
polymorphonuclear leukocyte dysfunction characterized by inability to generate hydrogen peroxide causing prolonged intracellular survival of phagocytized catalase-positive bacteria with dissemination in reticuloendothelial system |
| Organism: |
most commonly staphylococcus, Serratia marcescens, Nocardia species, mycobacteria, fungi |
| Path: |
chronic infection with granuloma formation/caseation/suppuration |
| Age: |
onset in childhood; M > F (more severe in boys) |
| Rx: |
prophylactic long-term trimethoprim-sulfamethoxazole + interferon gamma therapy |
Cirrhosis
| Associated with: |
anemia, coagulopathy, hypoalbuminemia, cholelithiasis, pancreatitis, peptic ulcer disease, diarrhea, hypogonadism |
• anorexia, weakness, fatigue, weight loss
• jaundice, continuous low-grade fever
• ascites, bleeding from esophageal varices, hepatic encephalopathy
enlarged (early stage)/normal/shrunken liver
-
shrinkage of right lobe (segments 5–8) and medial segment of left lobe (segments 4a + 4b) with concomitant hypertrophy of lateral segment of left lobe (segments 2 + 3) and caudate lobe (segment 1):
ratio of width of caudate to right lobe >0.65 on transverse images [sensitivity 43–84%, least sensitive in alcoholic cirrhosis, most sensitive in cirrhosis caused by hepatitis B; specificity 100%; 26% sensitivity; 84–96% accuracy] (DDx: Budd-Chiari syndrome)
diameter of quadrate lobe (segment 4) <30 mm (= distance between left wall of gallbladder and ascending portion of left portal vein) due to selective atrophy (95% specific)
widened porta hepatis + interlobar fissure
surface nodularity + indentations (regenerating nodules)
signs of portal hypertension
splenomegaly
ascites (failure of albumin synthesis, overproduction of lymph due to increased hydrostatic pressure in sinusoids/decreased splanchnic output due to portal hypertension)
associated with fatty infiltration (in early cirrhosis)
-
US (sensitivity 65–80%; DDx: chronic hepatitis, fatty infiltration):
-
Hepatic signs:
surface nodularity (54% sensitive, 95% specific)
caudate lobe hypertrophy (41% sensitive, 91% specific)
“portalization” of hepatic vein waveform = dampened oscillations of hepatic veins resembling portal vein flow (57% sensitive, 76% specific)
hepatomegaly (in 63%)
-
increased hepatic parenchymal echogenicity in 66% (as a sign of superimposed fatty infiltration):
increased sound attenuation (9%)
decreased/normal definition of walls of portal venules (sign of associated fatty infiltration NOT of fibrosis)
heterogeneous coarse (usually)/fine echotexture (in 7%)
occasional depiction of isoechoic regenerative nodules
dilatation of hepatic arteries (increased arterial flow) with demonstration of intrahepatic arterial branches (DDx: dilated biliary radicals)
-
increase in hepatic artery resistance (mean RI of 0.58–0.66 in normals to 0.63–0.85 in cirrhotics):
blunted increase in RI after meal ingestion (from 42% in normals to 7% in cirrhotics)
-
Extrahepatic signs:
splenomegaly
ascites
signs of portal hypertension
-
CT:
native + enhanced parenchymal inhomogeneity
decreased attenuation (steatosis) in early cirrhosis
isodense/hyperdense (siderotic) regenerative nodules
nodular/lobulated liver contour
predominantly portal venous supply to dysplastic nodules
hypodense area adjacent to portal vein (= peribiliary cysts from obstructed extramural peribiliary glands)
rapid tapering of intrahepatic portal + hepatic venous branches
-
CECT:
enlarged tortuous hepatic artery (compensatory increase in arterial blood flow)
arterioportal shunts (through trans-sinusoidal shunts in liver periphery + transplexal shunts with hypertrophy of peribiliary plexus) in hepatic arterial phase:
-
poorly demarcated transient peripheral wedge-shaped hepatic parenchymal enhancement
| DDx: |
hepatocellular carcinoma (defect on portal venous phase) |
early retrograde enhancement of portal vein branches
-
hepatofugal flow
| Cause: |
with occlusion of small hepatic venules the portal vein turns from a supplying vein into a draining vein |
-
MR (problem-solving tool):
no alteration of liver parenchyma
-
regenerative nodules ((due to iron deposits within nodules):
hypo-/isointense relative to liver on T1WI
hypointense on T2WI
no enhancement
dysplastic nodule = iso-/hyperintense on T1WI + iso-/hypointense on T2WI
HCC nodule = hypo-/iso-/hyperintense on T1WI + usually hyperintense on T2WI with marked enhancement during arterial phase
generalized decreased hepatic signal intensity on T2WI (mild iron deposition for unknown reasons)
-
Angio:
stretched hepatic artery branches (early finding)
enlarged tortuous hepatic arteries = “corkscrewing” (increase in hepatic arterial flow)
shunting between hepatic artery and portal vein
mottled parenchymal phase
delayed emptying into venous phase
pruning of hepatic vein branches (normally depiction of 5th order branches) = postsinusoidal compression by developing nodules
-
NUC (Tc-99m–labeled sulfur colloid):
high blood pool activity secondary to slow clearance
colloid shift to bone marrow + spleen + lung
shrunken liver with little or no activity + splenomegaly
mottled hepatic uptake (pseudotumors) on colloid scan (normal activity on IDA scans!)
displacement of liver + spleen from abdominal wall by ascites
| Cx: |
(1) Ascites: cause/contributor to death in 50%
(2) Portal hypertension
(3) Hepatocellular carcinoma (in 7–12%)
(4) Cholangiocarcinoma |
Fatality from:
esophageal variceal bleeding (in 25%), hepatorenal syndrome (10%), spontaneous bacterial peritonitis (5–10%), complications from treatment of ascites (10%)
Primary Biliary Cirrhosis
| Histo: |
idiopathic progressive destructive cholangitis of interlobar and septal bile ducts, portal fibrosis, nodular regeneration, shrinkage of hepatic parenchyma |
| Age: |
35–55 years; M:F = 1:9 |
Associated autoimmune disorders:
rheumatoid arthritis, Hashimoto thyroiditis, Sjögren syndrome, scleroderma, sarcoidosis
66–100% of patients with primary biliary cirrhosis have sicca-complex signs of the Sjögren syndrome
• fatigue, pruritus
• xanthelasma/xanthoma (25%)
• hyperpigmentation (50%)
• insidious onset of pruritus (60%)
• IgM increased (95%)
• positive antimitochondrial antibodies (AMA) in 85–100%
normal extrahepatic ducts
cholelithiasis in 35–39%
CT:
scattered dilated intrahepatic ducts with no apparent connection to main bile ducts
-
caudate lobe hypertrophy (in 98%):
hypertrophied hyperattenuating caudate lobe surrounded by hypoattenuating rindlike right lobe (pseudotumor)
atrophy of lateral segment of left hepatic lobe
intrahepatic biliary calculi (20%)
NUC:
marked prolongation of hepatic Tc-99m IDA clearance
uniform hepatic isotope retention
normal visualization of GB and major bile ducts in 100%
| DDx: |
(1) Sclerosing cholangitis (young men)
(2) CBD obstruction |
| Prognosis: |
mean survival 6 (range 3–11) years after onset of cholestatic symptoms |
Complications of End-Stage Liver Disease
Hepatopulmonary Syndrome
| Dx: |
(1) chronic liver disease
(2) increased alveolar-arterial gradient
(3) intrapulmonary vascular dilatation |
Hepatic Hydrothorax
| Prevalence: |
10% |
| Mechanism: |
pressure gradient favors fluid movement from peritoneal to pleural cavity through small diaphragmatic defects |
pleural fluid: right in 67%, left in 17%, bilateral in 17%
Pulmonary Hypertension
| Prevalence: |
0.73% in patients with liver cirrhosis (versus 0.13% in all patients) |
-
Cause:
thromboembolic: portal venous thrombus reaches lung through spontaneous/surgically created portosystemic shunts
plexogenic: vasoactive substances (serotonin, thromboxane, neuropeptide Y, elastase) bypass the liver through portosystemic shunts
| Prognosis: |
mean survival of 15 months |
Clonorchiasis
| Country: |
endemic to Southeast Asia: Japan, Korea, Central + South China, Taiwan, Indochina |
| Organism: |
Chinese liver fluke = Clonorchis sinensis |
| Cycle: |
parasite cysts digested by gastric juice, larvae migrate up the bile ducts, remain in small intrahepatic ducts until maturity (10–30 mm in length), travel to larger ducts to deposit eggs |
| Infection: |
snail + freshwater fish serve as intermediate hosts; infection occurs by eating raw fish; hog, dog, cat, man are definite hosts |
| Path: |
(a) desquamation of epithelial bile duct lining with adenomatous proliferation of ducts + thickening of duct walls (inflammation, necrosis, fibrosis)
(b) bacterial superinfection with formation of liver abscess |
| Cx: |
(1) Bile duct obstruction (conglomerate of worms/adenomatous proliferation)
(2) Calculus formation (stasis/dead worms/epithelial debris)
(3) Jaundice in 8% (stone/stricture/tumor)
(4) Generalized dilatation of bile ducts (2%) |
Congenital Biliary Atresia
| Etiology: |
? variation of same infectious process as in neonatal hepatitis with additional component of sclerosing cholangitis or vascular injury |
| Prevalence: |
<10 in 100,000 live births |
| Age: |
neonate; M:F = 2:1 |
| Histo: |
periportal fibrosis, proliferation of small intrahepatic bile ducts, mixed inflammatory infiltrates |
| In 15% associated with: |
polysplenia, trisomy 18 |
Types:
| I |
Focal = intrauterine vascular insult (extremely rare) |
| II |
Intrahepatic biliary atresia = paucity of intrahepatic bile ducts (uncommon) |
| III |
Extrahepatic biliary atresia = atresia of CBD + patent intrahepatic bile ducts |
-
Subtype 1 = perinatal type (66%)
-
Subtype 2 = embryonic/fetal type (34%)
Associated with: polysplenia (10–12%), intestinal malrotation, azygos continuation of IVC, symmetric bilobed liver, situs inversus, preduodenal portal vein, anomalous hepatic arteries, bilobed right lung, complex CHD
 |
| Biliary Atresia |
US:
normal/increased size of liver
normal/increased liver echogenicity
decreased visualization of peripheral portal veins (due to fibrosis)
“triangular cord”/tubular echogenic structure in porta hepatis (due to fibrous tissue) = PATHOGNOMONIC
-
gallbladder findings:
nonvisualization of gallbladder
small gallbladder <1.5 cm in length + varying degrees of luminal compromise (DDx: hepatitis)
normal gallbladder >1.5 cm in length (19%) when atresia of CBD distal to insertion of cystic duct
-
bile duct findings:
no dilatation of intrahepatic bile ducts (due to panductal sclerosis)
± visualization of bile duct remnant in porta hepatis (depending on type of biliary atresia)
small focal cystic dilatation of extrahepatic bile duct (= choledochal cyst) = patent segment of CBD with other parts being occluded due to fibrosis ± communication with gallbladder/intrahepatic bile ducts
NUC [phenobarbital-augmented cholescintigraphy] (90–97% sensitive, 60–94% specific, 75–90% accurate):
| DDx: |
severe hepatocellular dysfunction (DDx from neonatal hepatitis impossible in the absence of small bowel activity) requires liver biopsy |
MR cholangiography:
nonvisualization of extrahepatic bile ducts
atrophic gallbladder
periportal thickening
Cholangiography (percutaneous/endoscopic/intraoperative) Liver Bx (60–97% accurate)
| Rx: |
- Roux-en-Y choledochojejunostomy (20%);
- Kasai procedure = portoenterostomy (80%)
- child <60 days of age: 91% success rate
- child between 60 and 90 days of age: 50% success rate (due to developing cirrhosis)
- child >90 days of age: 17% success rate
- Liver transplant
|
DDx:
Neonatal hepatitis
Sclerosing cholangitis
Alagille syndrome = arteriohepatic dysplasia (abnormal facies, butterfly vertebra, pulmonic stenosis, complex CHD)
Congenital Hepatic Fibrosis
= congenital cirrhosis with rapid + fatal progression
| Histo: |
fibrous tissue within hepatic parenchyma with excess numbers of distorted terminal interlobular bile ducts + cysts that rarely communicate with bile ducts |
| Age: |
early childhood–6th decade; majority diagnosed in adolescence/early adulthood |
Associated with:
autosomal recessive polycystic kidney disease (invariably), Meckel-Gruber syndrome, vaginal atresia, tuberous sclerosis, nephronophthisis, medullary sponge kidney (80%), autosomal dominant polycystic kidney disease (rare)
| Cx: |
cirrhosis, portal hypertension, hepatocellular carcinoma, cholangiocellular carcinoma |
Echinococcal Disease Of Liver
Echinococcus Granulosus
| Cycle: |
ingestion of contaminated material (eggs passed in feces of dog/other carnivore); eggs hatch in duodenum; larvae penetrate intestinal wall + mesenteric venules; larvae carried into portal circulation; larvae are filtered in capillaries of liver (first line of defense) > lung > other organs |
Histo:
CYST FLUID = antigenic clear/pale yellow fluid with neutral ph containing sodium chloride, proteins, glucose, ions, lipids, polysaccharides
-
ENDOCYST (parasitic component of capsule) = inner GERMINATIVE LAYER (resembling wet tissue paper) giving rise to brood capsules (daughter vesicles), which may
remain attached to cyst wall harboring up to 400,000 scolices
detach + form sediment in cyst fluid = “hydatid sand”
break up into numerous self-contained daughter cysts
ECTOCYST = CYST MEMBRANE = acellular laminated chitinlike substance secreted by parasite, allowing passage of nutrients
PERICYST = dense fibrous protective zone of host granulation tissue replacing tissue necrosis (from compression by the expanding cyst); marginal vascular rim of 0.5–4 mm
pain/asymptomatic
recurrent jaundice + biliary colic (transient obstruction by membrane fragments + daughter cysts expelled into biliary tree)
blood eosinophilia (20–50%)
urticaria + anaphylaxis (following rupture)
-
Tests:
Casoni intradermal test (60% sensitivity; may be falsely positive)
Complement fixation double diffusion (65% sensitivity)
Immunoelectrophoresis (most specific)
Indirect hemagglutination (85% sensitivity)
 |
| Parasitic Cycle Of Echinococcus Granulosus |
| Time to diagnosis: |
11–81 (mean 51) years |
Affected organs:
| Location: |
right lobe > left lobe of liver; multiple cysts in 20% |
| Size: |
up to 50 cm (average size of 5 cm), up to 16 liters of fluid; grows 2–3 cm annually |
Stages of cyst growth:
Plain film:
-
peripheral crescentic/curvilinear/polycyclic calcifications (10–20–33%), located in pericyst:
Only complete calcification of all layers implies death of parasite!
pneumohydrocyst (infection/communication with bronchial tree)
US:
-
complex heterogeneous mass mimicking a solid mass (most common):
Look for membranes/peripheral daughter vesicles
-
well-defined anechoic cyst (common):
cyst wall of double echogenic lines separated by hypoechoic layer
“snowstorm sign” = multiple internal echogenic foci settling to most dependent portion of cyst (= hydatid sand)
-
multivesicular cyst of “racemose”/honeycomb appearance = multiple septa between daughter cysts inside mother cyst, CHARACTERISTIC but rare:
“wheel spoke” pattern = daughter cysts separated by echogenic material of hydatid matrix composed of broken daughter vesicles + scolices + hydatid sand
HIGHLY SPECIFIC serpentine linear structures within hydatid matrix
-
partial/complete detachment of endocyst from pericyst (due to decreasing intracystic pressure as a sign of degeneration/trauma/host response/response to therapy):
localized split in wall with floating undulating membrane, CHARACTERISTIC but rare
“water lily sign” = complete detachment of membrane
Floating membrane does not indicate death of parasite!
eggshell calcification in cyst wall (least common)
CT:
-
well-demarcated round low-density mass of fluid attenuation (3–30 HU):
cyst wall of high attenuation on NECT
linear areas of increased attenuation = detached laminated membrane
round peripheral fluid collection of lower attenuation (= daughter cysts)
enhancement of cyst wall + septations
calcification of cyst wall/internal septa
MR:
cyst with hypointense rim (= collagenous pericyst) on T1WI + T2WI
peripheral cysts within cyst hypointense on T1WI + hyperintense on T2WI (= daughter cysts)
twisted linear structures within cyst = collapsed parasitic membrane
Angio:
avascular area with splaying of arteries
halo of increased density around cyst (inflammation/compressed liver)
Cholangiography:
cyst may communicate with bile ducts: right hepatic duct (55%), left hepatic duct (29%), CHD (9%), gallbladder (6%), CBD (1%)
Percutaneous aspiration:
Local Cx:
-
Rupture (50–90%)
-
contained = rupture of laminated membrane of endocyst, pericyst remains intact
floating membranes
communicating = cyst contents escapes through biliary (5–15%)/bronchial tree
direct = tear of endocyst + ectocyst + pericyst with cyst contents spilling into pleural/peritoneal cavity (anaphylaxis, metastatic hydatidosis)
Infection (5–8%) following rupture
-
Transdiaphragmatic growth (0.6–16%) through bare area of liver
rupture into pleural cavity
seeding in pulmonary parenchyma
chronic bronchial fistula
Perforation into hollow viscus (0.5%)
Peritoneal seeding (13%) = encysted peritoneal hydatidosis
Compression of vital structures (bile ducts, portal vein)
| Rx: |
(1) Surgery (in 10% recurrence)
(2) Anthelmintics (albendazole, medendazole)
(3) Injection of scolecidal agents (silver nitrate, 20/30% hypertonic saline solution,0.5% cetrimide solution, 95% ethanol) |
Echinococcus Multilocularis
| Primary host: |
fox, wolf |
| Secondary host: |
rodents (moles, lemmings, wild mice); domestic cat; dog |
| Endemic to: |
eastern France, southern Germany, western Austria, much of Soviet Union, Japan, Alaska, Canada, some areas in Turkey |
| Infection: |
eating wild fruits contaminated with fox/wolf feces; direct contact with fox/wolf; contact with dogs/cats that have ingested infested rodents |
| Path: |
larvae proliferate by exogenous extension + penetration of surrounding tissue (= diffuse + infiltrative process resembling malignancy); chronic granulomatous reaction with central necrosis, cavitation, calcification |
| Histo: |
daughter cysts with thick lamellar wall arising on outer surface of original cyst, rarely containing scolices |
| Location: |
liver (access via portal vein); widespread hematogenous dissemination not uncommon |
• clinical manifestation 5–20 years after ingestion
• abdominal discomfort, jaundice, hepatomegaly
• eosinophilia
-
aggressive growth pattern:
geographic infiltrating lesion with ill-defined margins
invasion of IVC, diaphragm
metastases to lung, heart, brain (in 10%)
faint/dense amorphous coalescent nodular/flame-shaped calcifications (dystrophic central calcifications scattered throughout necrotic + granulomatous tissue)
US:
echogenic geographic ill-defined single/multiple solid masses
± irregular cystic areas
propensity of spread to liver hilum
CT:
heterogeneous hypodense poorly marginated infiltrating masses
pseudocystic necrotic regions of near water density surrounded by hyperdense solid component
little/no enhancement
Angio:
intrahepatic arterial tapering + obstruction
| Cx: |
Budd-Chiari syndrome, IVC thrombosis, portal hypertension |
| Prognosis: |
fatal within 10–15 years (if left untreated) |
| DDx: |
hepatocellular carcinoma (biopsy!), large hemangioma (characteristic enhancement pattern), metastasis, epithelial hemangioendothelioma |
Embryonal Rhabdomyosarcoma Of Biliary Tree
rare tumor most commonly arising from CBD
| Median age: |
3 years; M > F |
| Path: |
intraluminal biliary mass/cluster of grapelike masses (similar to rhabdomyosarcoma of bladder) |
| Histo: |
same as sarcoma botryoides |
• malaise, fever, jaundice
• elevation of conjugated bilirubin
-
Metastases (in up to 30%) to:
| Location: |
common bile duct (most frequently) |
8–20-cm bulky heterogeneous mass in porta hepatis
intrahepatic bile duct dilatation
displacement of duodenum, stomach, pancreas
-
Cholangiography:
large bulky intraluminal mass/grapelike cluster of intraluminal masses focally distending common bile duct + obstructing proximal bile ducts
Epidermoid Cyst Of Spleen
EPITHELIAL CYST = PRIMARY CYST OF SPLEEN
| Incidence: |
10% of all benign nonparasitic cysts |
| Cause: |
infolding of peritoneal mesothelium/collection of peritoneal mesothelial cells trapped within splenic sulci |
| Histo: |
(1) mesothelial lining
(2) squamous epithelial lining = epidermoid cyst = squamous metaplasia from embryonic inclusions within preexisting mesothelial surface epithelium |
| Age: |
2nd–3rd decade (average age of 18 years) |
| May be associated with: |
polycystic kidney disease |
well-defined thin-walled anechoic lesion of water density
average size of 10 cm
peripheral septations/cyst wall trabeculations (in 86%)
curvilinear calcification in wall (9–25%)
may contain cholesterol crystals, fat, blood
| Cx: |
trauma, rupture, infection |
Eosinophilic Cholangiopathy
rare benign cause of biliary obstruction
| Incidence: |
15 cases in literature |
| Cause: |
unknown |
| Histo: |
transmural eosinophilic infiltration of biliary tract |
| May be associated with: |
multiple organ involvement (in 50%) of GI tract, urinary tract, bone marrow, pancreas, lymph nodes |
| Rx: |
steroids |
| DDx: |
lymphoma, AIDS cholangiopathy, collagen vascular disease, cholangiocarcinoma, amyloidosis |
Epithelioid Hemangioendothelioma
rare primary malignant vascular tumor of liver (soft tissue, bone, lung)
| Age: |
average age of 45 years; M:F = 1:2 |
| May be associated with: |
oral contraceptives, exposure to vinyl chloride |
| Path: |
multifocal nodules varying in size from a few mm to several cm involve both lobes of the liver (due to rapid perivascular extension); nodules may coalesce in liver periphery |
| Histo: |
dendritic spindle-shaped cells + epithelioid round cells in a matrix of myxoid + fibrous stroma; neoplastic endothelial cells invade sinusoids + terminal hepatic + portal veins cutting off the tumor’s blood supply |
| Metastases to: |
spleen, mesentery, lymph nodes, lung, bone |
multiple nodules (nodular form)
peripheral subcapsular growth (diffuse form) without deforming liver contour
increased tumor vascularity
hypertrophy of uninvolved liver
Plain film:
hepatic calcifications within myxoid stroma (15%)
US:
typically hypoechoic lesions (due to central core of myxoid stroma)
CT:
low-attenuation masses on NECT, may become isoattenuating with rest of liver on CECT (due to vasoformative growth + compensatory hepatic arterial flow with portal vein occlusion)
Angio:
hyper- and hypovascularity (dependent upon degree of sclerosis + hyalinization)
invasion ± occlusion of portal + hepatic veins
NUC:
decreased perfusion to central myxoid tumor portion + increased perfusion to cellular areas on sulfur colloid scan
photopenic defect on static sulfur colloid scan
NOT gallium avid
| Prognosis: |
20% die within 2 years, 20% survive for 5–28 years ± treatment |
| DDx of multiple nodules: |
metastatic disease |
| DDx of diffuse form: |
sclerosing carcinoma, vasoocclusive disease |
Fatty Liver
FATTY INFILTRATION OF THE LIVER = HEPATIC STEATOSIS
Cause:
-
METABOLIC DERANGEMENT
poorly controlled diabetes mellitus (50%), obesity, hyperlipidemia, acute fatty liver of pregnancy, protein malnutrition, total parenteral hyperalimentation (TPN), malabsorption (jejunoileal bypass), glycogen storage disease, glycogen synthetase deficiency, cystic fibrosis, Reye syndrome, corticosteroids, severe hepatitis, trauma, chronic illness (TB, CHF)
-
HEPATOTOXINS
alcohol (>50%), carbon chlorides, phosphorus, amiodarone, chemotherapy
| Histo: |
hepatocytes with large cytoplasmic fat vacuoles containing triglycerides; >5% fat of total liver weight |
Diffuse fatty infiltration
Fat-Spared Area in diffuse fatty infiltration
| Cause: |
direct drainage of systemic blood into liver |
Location:
hypoechoic ovoid/spherical/sheetlike mass
No mass effect (undisplaced course of vessels)
Focal Fatty Infiltration
| Etiology: |
? vascular origin, focal tissue hypoxia |
| Distribution: |
(a) lobar/segmental uniform lesions
(b) lobar/segmental nodular lesions
(c) perihilar lesions
(d) diffuse nodular lesions
(e) diffuse patchy lesions
predominantly in centrilobar + periportal regions, subcapsular distribution may be due to variants of blood supply (due to “third inflow” from connection between peripheral portal radicles + perforating capsular/accessory cystic veins) |
| Location: |
right lobe, caudate lobe, perihilar region |
| DDx: |
primary/secondary hepatic tumor |
Focal Nodular Hyperplasia
FNH = rare benign congenital hamartomatous malformation or reparative process in areas of focal injury; SPECIFIC DIAGNOSIS RARELY POSSIBLE
| Prevalence: |
0.9%; 2nd most common benign tumor of liver after hemangioma; 3–8% of all primary hepatic tumors in adult population, 4% in pediatric population; twice as common as hepatocellular adenoma |
| Cause: |
(?) congenital arteriovenous malformation triggers focal hepatocellular hyperplasia owing to a regional increase in blood flow
♢ Oral contraceptives DO NOT cause FNH, but exert a trophic effect on its growth! |
| Path: |
localized, well-delineated, usually solitary (80–95%), subcapsular mass composed of numerous small nodules within an otherwise normal liver; no true capsule; frequently central fibrous scar in area of interconnection of fibrous bands (HALLMARK); angioarchitecture typically has one/more thick-walled arteries within fibrous septa dividing into numerous capillaries connected to sinusoids, which are drained by large hepatic veins (no portal veins!); FNH hepatocytes contain steatosis in 50% |
| Histo: |
composed of multiple spherical aggregates of hepatocytes often containing increased amounts of fat (in 50%) + triglycerides + glycogen; Kupffer cells line sinusoids; bile duct proliferation within fibrous septa without connection to biliary tree; thick-walled arteries within fibrous septa radiating from the center toward the periphery; absent portal triads + central veins; difficult differentiation from regenerative nodules of cirrhosis + hepatocellular adenoma |
Pathologic classification:
| Age peak: |
3rd–4th decade (range: 7 months to 75 years);
M:F = 1:8 |
| Associated with: |
hepatic hemangioma (in 23%), meningioma, astrocytoma, arterial dysplasia of other organs in case of multiple FNH |
initially often asymptomatic (in 50–90% incidental discovery)
vague abdominal pain (10–15%) due to mass effect
normal liver function
hepatomegaly/abdominal mass
| Location: |
right lobe:left lobe = 2:1; multiple in 20% |
| Size: |
<5 cm (in 85%) |
-
well-circumscribed
nonencapsulated nodular cirrhotic-like mass in an otherwise normal liver:
often near liver surface
pedunculated mass (in 5–20%)
multiple masses (in 20%)
central stellate scar = central fibrous core with radiating fibrous septa containing arteriovenous malformation= spoke-wheel pattern (in 50%)
-
highly vascular tumor:
supplied by enlarged anomalous hepatic artery
venous drainage always into hepatic veins(DDx: HCC drains into portal vein system in 98%)
hemorrhage is unlikely
pseudocapsule of a few mm in thickness (due to surrounding compressed hepatic parenchyma, perilesional vessels, inflammatory reaction)
calcifications are EXTREMELY rare
NECT:
iso-/slightly hypoattenuating homogeneous mass
CECT (3 phases necessary!):
transient intense hyperdensity of most of the lesion during arterial phase (30–60 sec after bolus injection) except for central scar
hypodense central scar during arterial phase (15–33%) (DDx: fibrolamellar HCC)
lesion becomes isodense during portal venous + equilibrium phase
hyperdense central scar on delayed images (delayed washout of contrast from myxomatous scar tissue)
US:
iso-/mildly hypo-/mildly hyperechoic (33%) homogeneous mass
hypoechoic halo (of compressed liver parenchyma/displaced hepatic vessels)
hyperechoic central scar in 18%
Doppler:
enlarged afferent blood vessel with central arterial hypervascularity + centrifugal filling to the periphery in a “spoke-wheel” pattern
large draining veins at tumor margins
may show high-velocity Doppler signals with arterial pulsatility from arteriovenous shunts
MR (70% sensitive, 98% specific, requires 3 phases):
usually homogeneous signal intensity of lesion
-
T1WI:
iso- to hypointense (94–100%)
atypically hyperintense lesion in 6%
T2WI: slightly hyper- to isointense (94–100%)
-
central scar (more often detected than on US/CT)
hypointense on T1WI
hyperintense on T2WI in 75–84% (due to vascular channels + edema)
hypointense on T2WI in 25% (absent or minimal edema)
CEMR (2-D/3-D GRE):
intense enhancement in arterial phase
isointense during portal venous phase
late + prolonged enhancement of central scar (due to increased interstitial space + fluid content gradually taking up contrast material)
occasionally prolonged enhancement (due to entrapment of Gd-DTPA by functioning hepatocytes inside tumor followed by 1% excretion into biliary tree)
enhancement of pseudocapsule on delayed images
-
less uptake of IV superparamagnetic iron oxide (ferucarbotran, mangafodipir trisodium) than surrounding
liver (uptake mechanism similar to that of sulfur colloid)
Use iron oxide in lesions with atypical features!
NUC:
-
Sulfur colloid scan:
Only FNH contains sufficient Kupffer cells to cause normal/increased uptake
normal uptake (33%)
increased uptake (33%) = virtually DIAGNOSTIC
cold spot (33%) due to less Kupffer cells (DDx: hepatic adenoma, hemangioma, hepatoblastoma, liver herniation, hepatocellular carcinoma)
Tc-HIDA:
normal/increased uptake (40–70%), cold spot (60%)
Tc-99m–tagged RBCs:
increased uptake during early phase
defect relative to liver on delayed images
Angio:
discretely marginated hypervascular mass (90%) with intense capillary blush/hypovascular (10%)
enlargement of main feeding artery with central blood supply (= “spoke-wheel” pattern in 33%)
homogeneous parenchymal stain
decreased vascularity in central stellate fibrous scar
| Rx: |
(1) Discontinuation of oral contraceptives
(2) Resection of pedunculated mass
(3) Diagnostic excisional biopsy for extensive tumor (FNH seldom requires surgery) |
| Cx: |
rarely rupture with hemoperitoneum (increased incidence in patients on oral contraceptives — 14%) |
DDx:
Fibrolamellar carcinoma (scar calcified, metastases, retroperitoneal adenopathy, tumor hemorrhage + necrosis causing pain, hypointense scar on T2WI)
Hepatic adenoma (10 cm large tumor, symptomatic due to propensity for hemorrhage in 50%, central scar atypical)
Well-differentiated hepatocellular carcinoma (internal necrosis + hemorrhage, vascular invasion, metastases, persistent rim-enhancement of tumor capsule)
Giant cavernous hemangioma (larger tumor, may calcify, globular peripheral enhancement followed by centripetal filling, retention of contrast on delayed images, central scar with CSF-like behavior on MRI)
Hypervascular metastasis (hypovascular during portal venous phase, older patient)
Intrahepatic cholangiocarcinoma (less vascular, dominant large central scar, metastases)
Telangiectatic Focal Nodular Hyperplasia
| Frequency: |
10% of all FNH |
| Age: |
mean age 38 years; women |
| Associated with: |
oral contraceptives (mean time, 15 years) |
| Mean size: |
7 cm |
multiple lesions in 20–50%
strong arterial enhancement
persistent lesion enhancement (61%) due to sinusoidal dilatation
absence of a central scar (92%)
heterogeneous pattern (43%) due to necrosis, sinusoidal dilatation, hemorrhagic foci
MR:
hyperintensity on T1WI (53%) due to intrasinusoidal dilatation
strong hyperintensity on T2WI (44%)
Gallbladder Carcinoma
| Incidence: |
0.4–4.6% of biliary tract operations; most common biliary cancer (9 × more common than extrahepatic bile duct cancer); 6th most common gastrointestinal malignancy (after colon, pancreas, stomach, liver, esophagus); 3% of all intestinal neoplasms; 7,000 new cases/year in United States |
| Demographics: |
most common in Israel, Bolivia, Chile, northern Japan, New Mexico |
| Ethnicity: |
Native Americans + Hispanic Americans (associated with increased prevalence of gallstones) |
| Median age: |
72 years; M:F = 1:3–1:4; whites > blacks
♢ 85% occur in 6th decade or later! |
| Risk factors: |
increased body mass, female gender, postmenopausal status, cigarette smoking, chronic Salmonella typhi infection, exposure to chemicals (rubber, automobile, wood finishing, metal fabricating industries) |
Associated with:
| Path: |
diffusely infiltrating lesion (68%), intraluminal polypoid growth (32%) |
| Histo: |
- (a) adenocarcinoma (76%):
–papillary (6% with tendency to fill gallbladder lumen)
–intestinal type (variant of well-differentiated adenocarcinoma with intestinal glands)
–mucinous (5%, with >50% extracellular mucin)
–signet-ring cell (abundant intracytoplasmic mucin)
–clear cell (well-defined cytoplasmic borders)
- (b) rare epithelial cell types:
–adenosquamous carcinoma (3%)
–squamous cell carcinoma (1%)
–small (oat) cell carcinoma (0.5%, highly aggressive, ± paraneoplastic Cushing syndrome)
–undifferentiated carcinoma
- (c) nonepithelial cell types (2%):
carcinoid, carcinosarcoma, basal cell carcinoma, lymphoma
|
Modified Nevin Stage:
| I |
mucosa only (in situ carcinoma) |
| II |
mucosal + muscular invasion |
| III |
mucosa + muscularis + serosa |
| IV |
gallbladder wall + lymph nodes |
| V |
hepatic/distant metastases |
| Location: |
fundus (60%), body (30%), neck (10%) |
Growth types:
mass replacing the gallbladder (40–65%)
-
thickening of GB wall (20–30%) due to submucosal spread:
focal (59%)/diffuse (41%) wall thickening
| DDx: |
acute/chronic inflammation (usually <10 mm) |
intraluminal polypoid/fungating “cauliflower-like” mass with wide base (15–25%)
replacement of gallbladder by mass (37–70%)
pericholecystic infiltration: in 76% focal, in 24% diffuse
-
dilatation of biliary tree (38–70%):
infiltrative tumor growth along cystic duct
lymph node enlargement causing biliary obstruction
intraductal tumor spread
fine granular/punctate flecks of calcification (mucinous adenocarcinoma)
lymph node enlargement in porta hepatis
| N.B.: |
misdiagnosis by US/CT in 50%, especially in the presence of gallstones |
Abdominal radiograph:
calcified gallstones
porcelain gallbladder
RUQ gas collection (after invasion of adjacent bowel)
Cholangiography:
malignant stricture/obstruction of extrahepatic bile ducts/right and left bile duct confluence, intrahepatic duct of right lobe
intraluminal GB filling defect (= tumor/stones)
mass displacing/invading gallbladder
intraductal filling defects (= tumor/stones)
US:
gallbladder replaced by mass with irregular margins + heterogeneous echotexture (= tumor necrosis)
-
immobile intraluminal well-defined round/oval mass
echogenic foci = coexisting gallstones/wall calcifications/tumoral calcification
tumor inseparable from liver
CT:
-
hypo-/isoattenuating mass in gallbladder fossa:
low-attenuation areas of necrosis
areas of enhancement (= viable tumor)
subtle extension beyond wall of GB
invasion of liver with protrusion of anterior surface of medial segment of left lobe
MR:
hypointense mass on T1WI + ill-defined early contrast enhancement
| Metastases: |
in 75–77% at time of diagnosis |
-
direct extension (most common mode): invasion of liver (34–65–89%), duodenum (12–15%), colon (9–15%), pancreas (6%), stomach, bile duct, right kidney, abdominal wall
| Cause: |
thin GB wall with only a single muscle layer + no substantial lamina propria + perimuscular connective tissue continuous with interlobular connective tissue of liver |
lymphatic spread (26–41–75%): cystic, pericholedochal, celiac, superior mesenteric, foramen of Winslow, paraaortic nodes, superior + posterior pancreaticoduodenal
intraperitoneal seeding (common)
hematogenous spread (less common): liver, lung, bones, heart, pancreas, kidney, adrenal, brain
neural spread (frequent): associated with more aggressive tumors
intraductal spread (least common): particularly in papillary adenocarcinoma
| Cx: |
perforation of gallbladder + abscess formation
√gallstones located within abscess |
| Prognosis: |
75% unresectable at presentation; average survival is 6 months; 5% 1-year survival rate; 6% 5-year survival rate |
| DDx: |
(1) Xanthogranulomatous cholecystitis (lobulated mass filling gallbladder + stones)
(2) Acute/chronic cholecystitis (generalized gallbladder wall thickening <10 mm)
(3) Liver tumor invading gallbladder fossa
(4) Tumors from adjacent organs (pancreas, duodenum)
(5) Metastases (melanoma, leukemia, lymphoma)
(6) Polyps: cholesterol polyp, hyperplastic polyp, granulation polyp
(7) Adenomyomatosis |
Glycogen Storage Disease
Von Gierke Disease (Type I)
| Etiology: |
defect in glucose-6-phosphatase with excess deposition of glycogen in liver, kidney, intestines |
| Dx: |
failure of rise in blood glucose after glucagon administration |
| Age at presentation: |
infancy |
hepatomegaly
-
US:
increased echogenicity (glycogen/fat)
-
CT:
increased (glycogen)/normal/decreased (fat) parenchymal attenuation
| Prognosis: |
death in infancy, may survive into adulthood with early therapy |
| Cx: |
(1) Hepatic adenoma
(2) Hepatocellular carcinoma |
Pompe Disease (Type II)
| Etiology: |
defect in lysosomal glucosidase |
massive cardiomegaly with CHF
hepatomegaly
| Prognosis: |
sudden death in 1st year of life (due to conduction abnormalities); survival rarely beyond infancy |
Andersen Disease (Type IV)
Hemochromatosis
excess iron deposition in various parenchymal organs (liver, pancreas, spleen, kidneys, heart) leading to cirrhosis with portal hypertension
| Cause: |
excess iron deposition from
- increased GI absorption:
- Genetic hemochromatosis
- Erythropoietic hemochromatosis
- Bantu siderosis
- IV blood transfusion
- intravascular (extrasplenic) hemolysis
|
CT (60% sensitivity for iron):
diffuse/rarely focal increase in liver density (up to 75–130 HU)
depiction of portal + hepatic veins against background of hyperattenuating liver on NECT
dual energy CT (at 80 + 120 kVp) can quantitate amount of iron deposition
Genetic Hemochromatosis
= IDIOPATHIC/PRIMARY/HEREDITARY HEMOCHROMATOSIS
= excessive duodenal absorption + parenchymal retention of dietary iron that favors accumulation within non-RES organs (liver, pancreas, heart, pituitary gland)
| Cause: |
autosomal recessive disorder (abnormal HFE gene located near human-leukocyte antigen [HLA] on short arm of chromosome 6) with increased absorption of intestinal iron |
| Prevalence: |
1:220 whites of northern European ancestry; homozygote frequency up to 0.25–0.50%; heterozygote carriers >10% |
Pathophysiology:
| Path: |
excess iron stored as crystalline iron oxide (ferric oxyhydroxide) within cytoplasmic ferritin + lysosomal hemosiderin; iron overload affects parenchymal cells (liver, pancreas, heart) NOT Kupffer cells/RE cells of bone marrow + spleen (abnormal function of RES) |
| Age: |
after middle age; female iron loss during menses and pregnancy provides some protection |
asymptomatic during 1st decade of disease
symptomatic in 80–90% if iron deposits >10 g
hyperpigmentation (90%)
hepatomegaly (90%)
arthralgias (50%)
diabetes mellitus (30%) secondary to insulin resistance by hepatocytes + pancreatic β-cell damage from iron deposition
CHF + arrhythmia (15%)
loss of libido, impotence, amenorrhea, testicular atrophy, loss of body hair
liver iron index > 2 (= liver iron concentration [μmol per gram of dry weight] per patient’s age)
serum Fe >300 mg/dL
serum transferrin saturation > 50%
MR:(skeletal muscle = good signal intensity reference)
significant signal loss in liver on T2WI with signal intensity equal to background noise (paramagnetic susceptibility of ferritin + ferric ions leads to profound shortening of T1 + T2 relaxation times of adjacent protons)
normal pancreatic signal intensity in noncirrhotics
pancreatic signal intensity equal to/less than muscle (in 90% of cirrhotic patients)
normal signal intensity of spleen (in 86%) due to abnormal RES function
normal bone marrow signal
| Dx: |
liver biopsy |
| Cx: |
(1) Periportal fibrosis resulting in cirrhosis (if iron concentration >22,000 μg/g of liver tissue)
(2) Hepatocellular carcinoma (14–30%)
(3) Insulin-dependent diabetes mellitus (30–60%)
(4) Congestive cardiomyopathy (15%) |
| Rx: |
phlebotomies in precirrhotic stage |
| Prognosis: |
normal life expectancy with early diagnosis and treatment |
Secondary Hemochromatosis
| Path: |
iron deposition initially in RES (phagocytosis of intact RBC) with sparing of parenchymal cells of pancreas; after saturation of RES storage capacity parenchymal cells of other organs accumulate iron (liver, pancreas, myocardium) |
| Age: |
4th–5th decade; M:F = 10:1 |
MR:
signal loss in liver on T2WI with signal intensity greater than background noise (iron in Kupffer cells with sparing of parenchymal liver cells)
splenic signal intensity less than muscle
low signal intensity of bone marrow (= siderotic marrow)
Transfusional Siderosis
= iron deposited in liver, spleen, and bone marrow in patients receiving >40 units of blood (iron storage capacity of RES = 10 g of iron)
• abnormal iron deposition in RES is clinically of little significance (no damage of affected organs)
parenchymal iron deposition can cause organ dysfunction
low signal intensity of bone marrow (= siderotic marrow)
strong signal decrease in spleen
low signal intensity of liver + pancreas
| Rx: |
iron chelation therapy to remove excess iron |
Hepatic Abscess
| Types: |
pyogenic (85%), fungal (9%), amebic (6%) |
| Location: |
multiple in 50% ♢ A pyogenic abscess tends to be centrally located, an amebic abscess peripherally! |
hepatomegaly
elevation of right hemidiaphragm
pleural effusion
right lower lobe atelectasis/infiltration
gas within abscess (esp. Klebsiella)
MR:
hypointense on T1WI + hyperintense on T2WI (72%)
perilesional edema (35%)
“double target sign” on T2WI = hyperintense center (fluid) + hypointense sharply marginated inner ring (abscess wall) + hyperintense poorly marginated ring (perilesional edema)
rim enhancement (86%)
Amebic Abscess
| Organism: |
Entamoeba histolytica |
| Etiology: |
spread of viable amebae from colon to liver via portal system |
| Incidence: |
in 1–25% of intestinal amebiasis |
| Age: |
3rd–5th decade; M:F = 4:1 |
amebic dysentery
amebic hepatitis (15%)
| Location: |
liver abscess (right lobe) in 2–25%; systemic dissemination by invasion of lymphatics/portal system (rare); liver:lung:brain = 100:10:1 |
| Size: |
2–12 cm; multiple liver abscesses in 25% |
nonspecific variable appearance
nodularity of abscess wall (60%)
internal septations (30%)
not gas-containing (unless hepatobronchial/hepatoenteric fistula present)
± disruption of diaphragm
CT:
nonspecific hypoattenuating area
enhancing wall
US:
homogeneous hypoechoic area
posterior acoustic enhancement
well-defined smooth thin wall
NUC:
sensitivity of sulfur colloid scan is 98%
photon-deficient area surrounded by rim of uptake on Ga-67 scan
Aspiration:
| Cx: |
(1) Diaphragmatic disruption (rare) is strongly suggestive of amebic abscess
(2) Fistulization into colon, right adrenal gland, bile ducts, pericardium |
| Rx: |
conservative treatment with chloroquine/metronidazole (Flagyl®); percutaneous drainage for left hepatic abscess (spontaneous rupture into pericardium + tamponade possible) |
| Prognosis: |
resolution under therapy may take from 1 month to 2 years; permanent cysts may remain behind |
Pyogenic Liver Abscess
Most common type of liver abscess
| Organism: |
E. coli, aerobic streptococci, St. aureus, anaerobic bacteria (45%); polymicrobial (>50%) |
| Incidence: |
0.016% |
| Predisposed: |
steroids, immunosuppressed state, excessive antibiotics usage |
Etiology:
| Age: |
6th–7th decade; M > F |
| Location: |
solitary abscess in right lobe (40–75%), in left lobe (2–10%); multiple abscesses in 10–34–73% (more often of biliary than hematogenous origin) |
US:
hypoechoic round lesion with well-defined mildly echogenic rim
posterior acoustic enhancement
coarse clumpy debris/low-level echoes/fluid-debris level with internal movement
intensely echogenic reflections with reverberations (from gas) in 20–30%
CT:
inhomogeneous hypoattenuating (0–45 HU) single/multiloculated cavity
“double target sign” = wall-enhancement + surrounding hypodense zone (6–30%)
“cluster sign” = several microabscesses each <2 cm within the same anatomic area; suggestive of biliary origin
air density
MR:
decreased T1 signal + increased T2 signal (varies with protein content)
enhancement of peripheral rim
NUC:
photon-deficient area on sulfur colloid + IDA scan
Ga-67 citrate uptake in 80%
In-111 tagged WBC uptake is highly specific (since WBCs normally go to liver, may need sulfur colloid test for correlation)
| Cx: |
(1) Septicemia
(2) Rupture into right subphrenic space
(3) Rupture into abdominal cavity
(4) Rupture into pericardium
(5) Empyema
(6) Common hepatic duct obstruction |
| Mortality: |
20–80%; 100% if unrecognized/untreated |
Hepatic Adenoma
| Prevalence: |
half as common as FNH |
| Path: |
pseudocapsule due to compression of liver tissue containing multiple large vessels; high incidence of hemorrhage + necrosis + fatty change; no scar |
| Histo: |
solitary spherical benign growth of hepatocytes; sheets of hepatocytes; sheets of hepatocytes without portal veins or central veins; scattered thin-walled vascular channels + bile canaliculi; decrease in number of abnormally functioning Kupffer cells; hepatocytes contain increased amounts of glycogen ± fat |
| Age: |
young women in childbearing age; not seen in males unless on anabolic steroids; rare in children |
Associated with:
oral contraceptives (2.5 × risk after 5-year use, 7.5 × risk after 9-year use, 25 × risk >9-year use)
anabolic steroids
pregnancy
diabetes mellitus
type Ia glycogen storage disease (von Gierke) in 60%
Fanconi anemia
| Location: |
right lobe of liver in subcapsular location (75%); multiple in 20–30% (eg, hepatic adenomatosis without risk factors) |
| Size: |
between 6 and 30 cm in size (average size of 8–10 cm) |
round well-circumscribed
pseudo-encapsulated mass
intraparenchymal/pedunculated (in 10%)
unusual “nodule-in-nodule” appearance in large tumors (DDx: hepatocellular carcinoma)
occasional eccentric dystrophic calcifications
CT:
round isoattenuating mass
mass of decreased density due to fat + areas of necrosis (30–40%)
hyperdense areas of fresh intratumoral hemorrhage (22–50%)
CECT:
transient avid enhancement on arterial-phase images in small adenomas/initial peripheral enhancement with centripetal filling in larger adenomas (due to supply by hepatic artery)
iso-/hypoattenuating on delayed-phase images
US:
-
usually small well-demarcated solid heterogeneous mass of variable echogenicity (echogenic for areas of fat or hemorrhage/complex hyper- and hypoechoic):
hyperechoic lesion with well-defined hypoechoic rim
anechoic cystic areas if large
color flow in peripheral peritumoral sinusoids
MR:
inhomogeneous on all pulse sequences (indistinguishable from HCC)
often hyperintense areas on T1WI (due to presence of fatladen hepatocytes/hemorrhage) in 35–77%
isointense sheets of hepatocytes on T2WI
hyperintense areas of necrosis/hemorrhage on T2WI in 47–74%
usually signal loss with out-of-phase imaging
NUC:
focal photopenic lesion on sulfur colloid scan (because lesion composed of hepatocytes + nonfunctioning Kupffer cells) surrounded by rim of increased uptake (due to compression of adjacent normal liver containing Kupffer cells); may show uptake equal to/slightly less than liver (23%)
usually increased activity on hIDA scan
No gallium uptake
Angio:
usually hypervascular mass
homogeneous but not intense stain in capillary phase
enlarged hepatic artery with feeders at tumor periphery (50%)
hypo-/avascular regions (secondary to hemorrhage/necrosis)
neovascularity
| CAVE: |
percutaneous biopsy carries high risk of bleeding! |
| Cx: |
(1) Spontaneous hemorrhage with subcapsular hematoma/hemoperitoneum (41%)
(2) Malignant transformation (? contiguous development of hepatocellular carcinoma)
(3) Recurrence after resection |
| Rx: |
hormone therapy stopped; screening for malignant degeneration with α-fetoprotein; surgical resection (to prevent rupture) |
| DDx: |
FNH, hemangioma, fibrolamellar hepatocellular carcinoma; metastasis |
Hepatic Angiomyolipoma
rare benign mesenchymal tumor
| Associated with: |
tuberous sclerosis |
| Histo: |
smooth muscle cells, fat, proliferating blood vessels |
• asymptomatic
intratumoral fat is DIAGNOSTIC
soft-tissue component may enhance
| Cx: |
intratumoral hemorrhage |
Hepatic Angiosarcoma
HEMANGIOENDOTHELIAL SARCOMA = KUPFFER CELL SARCOMA = HEMANGIOSARCOMA
| Prevalence: |
0.14–0.25 per million; <2% of all primary liver neoplasms; most common sarcoma of liver (followed by fibrosarcoma > malignant fibrohistiocytoma > leiomyosarcoma) |
Etiology:
| Associated with: |
hemochromatosis, anabolic steroids, cirrhosis, von Recklinghausen disease |
Path:
Histo:
vessels lined with malignant endothelial cells (eg, sinusoids) causing atrophy of surrounding liver
vasoformative = forming poorly organized vessels (responsible for RBC trauma + platelet trapping)
forming solid nodules of malignant spindle cells
| Age: |
6th–7th decade; M:F = 4:1 |
abdominal pain, weakness, fatigue, weight loss
spontaneous hemoperitoneum (27%)
jaundice
microangiopathic hemolytic anemia (23%), thrombocytopenia (54%), DIC (31%)
NO elevation of α-fetoprotein
Early metastases to:
lung (23%), spleen (16–46%), porta hepatis nodes, portal vein, thyroid, peritoneal cavity, bone marrow (rapid metastatic spread)
portal vein invasion
hemorrhagic ascites
Plain film:
circumferential displacement of residual thorotrast
NUC:
single/multiple photopenic areas on sulfur colloid scan
increased gallium uptake
perfusion blood pool mismatch (initial decrease followed by slow increase in RBC concentration) as in hemangioma on 3-phase red blood cell scan
US:
solid/mixed mass with anechoic areas (hemorrhage/necrosis)
multiple nodules
CT:
hypodense masses with high-density regions (hemorrhage)/low-attenuation regions (old hemorrhage/necrosis)
focal areas of peripheral enhancement on dynamic CT as in large hemangioma (60%)
MR:
hypointense on T1WI with irregular areas of high signal (hemorrhage)
hyperintense on T2WI + fluid-fluid levels
peripheral Gd-pentetate enhancement on T1WI
Angio:
hypervascular stain around tumor periphery in late arterial phase with puddling; NO arterial encasement
| CAVE: |
Biopsy may lead to massive bleeding in 16%! Have surgical backup available! |
| Prognosis: |
rapid deterioration with median survival of 6 months (13 months under chemotherapy) |
| DDx for multiple lesions: |
hypervascular metastases |
| DDx for single lesion: |
cavernous hemangioma, HCC (no splenic metastases) |
Hepatic Cyst
Second most common benign hepatic lesion after hemangioma
| Prevalence: |
2–7%; increasing with age; M < F |
-
ACQUIRED HEPATIC CYST
-
CONGENITAL HEPATIC CYST
| Incidence: |
liver cysts detected at autopsy in 50%;
in 22% detected during life |
| Age of detection: |
5th–8th decade |
| Histo: |
cyst surrounded by fibrous capsule + lined by columnar epithelium, related to bile ducts within portal triads; no communication with bile duct |
Associated with:
| Size of cyst: |
range from microscopic to huge (average 1.2 cm; in 25% largest cyst <1 cm; in 40% largest cyst >4 cm; maximal size of 20 cm) |
| Number of cysts: |
multiple cysts spread throughout liver (in 60%)/solitary cyst |
-
unilocular simple cyst:
imperceptible wall
may show fluid-fluid interface
water attenuation (0–10 HU)
no enhancement
“cold spot” on IDA, Ga-68, Tc-99m sulfur colloid scans
| Rx: |
sclerosing therapy with minocycline hydrochloride (Dose: 1 mg per 1-mL cyst content up to 500 mg in 10 mL of 0.9% saline + 10 mL 1% lidocaine) following contrast opacification of cyst to confirm absence of communication with biliary tree/leakage into peritoneal cavity |
Hepatic Hemangioma
Cavernous Hemangioma of Liver
| Incidence: |
1–4%; autopsy incidence 0.4–7.3%; increased with multiparity |
| Cause: |
? enlarging hamartoma present since birth,? true vascular neoplasm |
| Age: |
rarely seen in young children; M:F = 1:5 |
| Path: |
large vascular channels filled with slowly circulating blood; lined by single layer of mature flattened endothelial cells separated by thin fibrous septa; no bile ducts; thrombosis of vascular channels common resulting in fibrosis + hemorrhage + myxomatous degeneration + calcifications |
| Pathophysiology: |
large blood volume with low blood flow |
| Associated with: |
(1) Hemangiomas in other organs
(2) Focal nodular hyperplasia
(3) Rendu-Osler-Weber disease |
asymptomatic if tumor small (50–70%)
may present with spontaneous life-threatening hemorrhage if large (5%)
hepatomegaly
may enlarge during pregnancy
abdominal discomfort + pain (from thrombosis in large hemangioma)
Kasabach-Merritt syndrome (= hemangioma + thrombocytopenia) rare
| Location: |
frequently peripheral/subcapsular in posterior right lobe of liver; 20% are pedunculated; multiple in 10–20% |
| Size: |
<4 cm (90%); >4–6–12 cm = giant cavernous hemangioma
|
well-circumscribed lobulated mass
blood supply from hepatic artery
may have central area of fibrosis = areas of nonenhancement/nonfilling/cystic space (occurrence increases with age)
central septal calcifications within areas of fibrosis/phleboliths (5–20%)
US:
uniformly hyperechoic (60–70%) mass due to multiple interfaces created by blood-filled spaces separated by fibrous septa
inhomogeneous hypoechoic mass (up to 40%) in larger hemangiomas with well-defined thick/thin echogenic lobulated border due to hemorrhagic necrosis, scarring, myxomatous change centrally
homogenous (58–73%)/heterogeneous (fibrosis, thrombosis, hemorrhagic necrosis)
hypoechoic center possible
may show acoustic enhancement (37–77%)
unchanged in size/appearance (82%) on 1–6-year follow-up
no Doppler signals/signals with peak velocity of <50 cm/sec
CT (combination of precontrast images, good bolus, dynamic scanning):
-
well-circumscribed spherical/ovoid low-density mass:
may have areas of higher/lower density within mass
-
typical pattern of low density on NECT + peripheral enhancement + complete fill-in on delayed images 3–30 minutes post IV bolus (55–89%):
peripheral (72%)/central (in 8%)/diffuse dense (in 8%) enhancement
complete (75%)/partial (24%)/no (2%) fill-in to isodensity in delayed phase
-
rapid contrast filling (16%), more often in small lesions (in 42% of hemangiomas <1 cm)
| DDx: |
hypervascular tumor (do not remain hyperattenuating on delayed-phase images) |
central scar may not enhance at any time
MR (90–95% accuracy):
spheroid/ovoid (87%) mass with smooth well-defined lobulated margins (87%); no capsule
homogeneous internal architecture if <4 cm, hypointense internal inhomogeneities if >4 cm (due to fibrosis)
hypo-/isointense mass on T1WI
markedly hyperintense “light bulb” appearance (due to slow flowing blood) increasing with echo time) o T2WI (
DDx: hepatic cyst, hypervascular tumor, necrotic tumor, cystic neoplasm)
-
same enhancement pattern as CT:
uniform enhancement at 1 second in 40% of small hemangiomas <1.5 cm after gadolinium-DTPA
peripheral nodular enhancement progressing centripetally with centrally uniform enhancement (50%)/persistent hypointensity (30%)
mildly hyperintense on T2WI for hyalinized hemangioma + lack of enhancement in early phase + slight peripheral enhancement in late phase (DDx: malignant hepatic tumor)
Angio (historical gold standard):
dense opacification of well-circumscribed, dilated, irregular, punctate vascular lakes/puddles in late arterial + capillary phase starting at periphery in ring-/C-shaped configuration
normal-sized feeders; AV shunting (very rare)
contrast persistence late into venous phase
NUC (95% accuracy with SPECT):
| Indication: |
lesions >2 cm (detectable in 70–90%) |
initially cold lesion on Tc-99m labeled RBC scans (dose of 15–20 mCi) with increased activity on delayed images at 1–2 hours
cold defect on sulfur colloid scans
| Bx: |
may be biopsied safely provided normal liver is present between tumor + liver capsule
√nonpulsatile blood (73%)
√endothelial cells without malignancy (27%) |
| Prognosis: |
no growth when <4 cm in diameter; giant cavernous hemangiomas may enlarge |
| Cx (rare): |
(1) Spontaneous rupture (4.5%)
(2) Abscess formation
(3) Kasabach-Merritt syndrome (platelet sequestration) |
| DDx: |
hypervascular malignant neoplasm/metastasis (quick homogeneous filling during arterial phase of small hemangiomas) |
Giant Hepatic Cavernous Hemangioma
| Associated with: |
coexistent smaller <5 cm hemangioma in 13% |
| Histo: |
hemorrhage, thrombosis, extensive hyalinization, liquefaction, fibrosis; central cleft due to cystic degeneration/liquefaction |
US:
heterogeneous mass
NECT:
heterogeneous hypoattenuating mass with marked central areas of low attenuation
CECT:
early peripheral globular enhancement
incomplete filling of central portions
MR:
sharply marginated hypointense mass with cleftlike area of lower intensity on T1WI
large markedly hyperintense cleftlike area with some hypointense internal septa inside a hyperintense mass on T2WI
CEMR:
peripheral nodular enhancement
central cleftlike area remains hypointense
| DDx: |
metastasis, hepatocellular carcinoma, cholangiocarcinoma, hepatic adenoma, FNH (smaller and less hyperintense central scar on T2WI), focal fatty infiltration |
Infantile Hemangioendothelioma of Liver
| Histo: |
multiple anastomosing thick-walled vascular spaces similar to cavernous hemangioma lined by plump immature endothelial cells in single or (less often) multiple cell layers; areas of extramedullary hematopoiesis/thrombi; scattered bile ducts; involutional changes (infarction, hemorrhage, necrosis, scarring) |
Classification:
| Age at presentation: |
<6 months in 85%, during 1st month in 33%, >1 year in 5%; M: F = 1:1.4-1:2 |
abdominal mass secondary to hepatomegaly
cutaneous hemangiomas (9-45-87%) occur with multinodular form
may present with high-output ChF secondary to AV shunts within tumor (8 -15-25%)
-
Kasabach-Merritt syndrome (in 11%)
= hemorrhagic diathesis due to platelet sequestration by tumor/disseminated intravascular coagulation; characterized by an association of hemangioma, or hemangioendothelioma, or angiosarcoma with thrombocytopenia and purpura (secondary to increased systemic fibrinolysis)
| Prognosis: |
fatal outcome in 20-30% |
hemolytic anemia
| Size: |
several mm up to 20 cm (average size of 3 cm) |
diffuse involvement of entire liver, rarely focal
single mass (50%)/multiple masses (50%)
enlargement of celiac + hepatic arteries + proximal aorta
rapid decrease in aortic caliber below celiac trunk
enlarged hepatic veins (increased venous flow)
Plain film:
fine speckled/fibrillary calcifications in 16-25% (DDx: hepatoblastoma, hamartoma, metastatic neuroblastoma)
US:
heterogeneous predominantly hypoechoic/complex/hyperechoic lesion
-
multiple sonolucent areas (= enlarging vascular channels secondary to initial rapid growth) (DDx: mesenchymal hamartoma):
vascular components demonstrated by color Duplex
calcifications (in up to 50%)
OB-US:
polyhydramnios + fetal hydrops
NECT:
large well-defined hypoattenuating mass
hemorrhage (not uncommon)
calcifications (in up to 16%)
CECT (similar to cavernous hemangioma):
early peripheral enhancement (72%)
variable delayed central enhancement
MR:
heterogeneous hypointense multinodular lesion on T1WI ± hyperintense areas of hemorrhage
varying degrees of hyperintensity on T2WI (resembling adult hemangioma)
decreasing signal intensity with fibrotic replacement on T2WI
NUC (sulfur colloid, tagged RBC):
increased flow in viable portions of lesion during angiographic phase
increased activity mixed with central photopenic areas (hemorrhage, necrosis, fibrosis) on delayed tagged RBC images
photopenic defect on delayed sulfur colloid images
Angio:
enlarged, tortuous feeding arteries and stretched intrahepatic vessels
hypervascular tumor with inhomogeneous stain; clusters of small abnormal vessels
pooling of contrast material in sinusoidal lakes with rapid clearing through early draining veins (AV shunting)
| Prognosis: |
rapid growth in first 6 months followed by tendency to involute within 6–8 months; 32–75% survival rate in complicated cases |
| Cx: |
(1) Congestive heart failure
(2) Hemorrhagic diathesis
(3) Obstructive jaundice
(4) Hemoperitoneum (rupture of tumor) (5) Malignant transformation into angiosarcoma (rare) |
| Rx: |
(1) No treatment if asymptomatic
(2) Reduction in size with steroids/radiotherapy/chemotherapy
(3) Embolization(4) Surgical resection/liver transplantation |
| DDx: |
(1) Hepatoblastoma (>1 year of age, elevated α±-fetoprotein, more heterogeneous)
(2) Mesenchymal hamartoma (usually multilocular cystic mass) (3) Metastatic neuroblastoma (elevated catecholamines in urine, adrenal mass, nonenhancing multiple liver masses) |
Hepatic Venoocclusive Disease
| Etiology: |
radiation and chemotherapy in bone-marrow transplant patients; bush tea (alkaloid) consumption in Jamaica |
main hepatic veins + IVC normal
bidirectional/reversed portal venous flow
gallbladder wall thickening
Hepatitis
| Cause: |
alcohol, medication, viral infection, NASH (nonalcoholic steatohepatitis) |
Acute Hepatitis
CT:
periportal low attenuation (lymph edema)
US:
diffuse decrease in liver echogenicity
increased brightness of portal triads (“starry sky” pattern) = centrilobular pattern due to edema in hepatocytes (DDx: leukemic infiltrate, diffuse lymphomatous involvement, toxic shock syndrome)
edema of gallbladder fossa + gallbladder wall thickening
thickening + increase in echogenicity of fat within falciform ligament, ligamentum venosum, porta hepatis, periportal connective tissue
Chronic Hepatitis
| Cause: |
autoimmune hepatitis; hepatitis B, C, D; cryptic hepatitis; chronic drug hepatitis; primary biliary cirrhosis; primary sclerosing cholangitis; Wilson disease; alpha-1 antitrypsin deficiency |
US:
increased liver echogenicity
coarsening of hepatic echotexture
silhouetting/loss of definition of portal venules = decreased visualization of the walls of the peripheral portal veins
NO sound attenuation
| Cx: |
cirrhosis (10% for hepatitis B; 20–50% for hepatitis C) |
Neonatal Hepatitis
Cause:
INFECTION: virus, protozoa, spirochete, toxoplasmosis, rubella, CMV, herpes, hepatitis A/B, syphilis
METABOLIC: alpha-1 antitrypsin deficiency, familial recurrent cholestasis, errors of metabolism (nesidioblastosis = idiopathic hyperinsulin hypoglycemia of infancy)
IDIOPATHIC
| Age: |
1–4 weeks of age; M > F |
| Histo: |
multinucleated giant cells with hepatic parenchymal disruption, relatively little bile within bile duct canaliculi |
US:
normal-sized/enlarged liver
increase in parenchymal echogenicity
decreased visualization of peripheral portal veins
normal bile duct system
gallbladder of normal size/small (with decrease in bile volume in severe hepatocellular dysfunction)
decrease in gallbladder size after milk feeding (DDx: congenital biliary atresia)
NUC:
| Technique: |
often performed after pretreatment with phenobarbital (5 mg/kg × 5 days) to maximize hepatic function |
normal/decreased hepatic tracer accumulation
prolonged clearance of tracer from blood pool
bowel activity faint/delayed usually by 24 hours (best seen on lateral view; covering liver activity with lead shielding is helpful)
gallbladder may not be visualized
| Prognosis: |
spontaneous remission |
| DDx: |
biliary atresia (NO small bowel activity) |
Radiation Hepatitis
Acute Radiation-induced Hepatitis
| Time of onset: |
2–6 weeks after completion of radiation therapy with dose >3,500 rad (35 Gy) |
| Prognosis: |
complete recovery in majority |
Chronic Radiation-induced Hepatitis
increased attenuation in irradiated parenchyma (no fatty infiltration)
geographic areas of hypointensity on T1WI + hyperintensity on T2WI (due to increased water content)
| Viral Markers of Hepatitis |
| Virus |
Tests |
Interpretation |
| HAV |
Anti-HAV IgM |
acute hepatitis (can remain positive for >1 year) |
| Anti-HAV IgG |
past hepatitis, lifelong immunity |
| HBV |
HBsAg |
acute/chronic disease |
| Anti-HBc IgM |
acute infection (if titer high); chronic infection (if titer low) |
| Anti-HBc IgG |
past/recent HBV contact (may be only serum indicator of past infection) |
| HBe |
active viral replication |
| Anti-HBe |
low/absent replicative state (typically present in long-standing HBV carriers) |
| Anti-HBs |
immunity after vaccination |
| HBV-DNA |
active viral replication |
| HCV |
Anti-HCV |
past/current infection |
| RIBA |
test for various viral components |
| HCV-RNA |
active viral replication |
| HDV |
Anti-HDV IgM |
acute/chronic infection |
| Anti-HDV IgG |
chronic infection (if titer high + IgM positive); past infection if titer low + IgM negative) |
| HDV-RNA |
active viral replication |
| HEV |
Anti-HEV IgM |
acute hepatitis |
| Anti-HEV IgG |
past hepatitis |
| HEV-RNA |
viral replication |
Hepatoblastoma
| Incidence: |
3rd most common abdominal tumor in children; most frequent malignant hepatic tumor in infants + children <3 years of age |
| Incidence increased with: |
hemihypertrophy, Beckwith syndrome |
Histo:
epithelial type = small cells resembling embryonal/fetal liver
mixed type = epithelial cells + mesenchymal cells (osteoid, cartilaginous, fibrous tissue)
| Age: |
<3 years; <18 months (in 50%); peak age between 18 and 24 months; range from newborn to 15 years; M:F = 2:1 |
upper abdominal mass, weight loss, nausea, vomiting
jaundice, pain
precocious puberty (production of endocrine substances)
persistently + markedly elevated α-fetoprotein (66%)
| Metastases to: |
lung (frequent) |
| Location: |
right lobe of the liver |
usually solitary mass with an average size of 10–12 cm
multifocal (20%)
coarse calcifications/osseous matrix (12–30%)
US:
large heterogeneous echogenic mass, often with calcifications, occasionally cystic areas (necrosis/extramedullary hematopoiesis)
CT:
hypointense tumor with peripheral rim enhancement
MR:
inhomogeneously hypointense on T1WI with hyperintense foci (hemorrhage)
inhomogeneously hyperintense with hypointense bands (fibrous septa) on T2WI
NUC:
photopenic defect
Angio:
hypervascular mass with dense stain
marked neovascularity; NO AV-shunting
vascular lakes may be present
avascular areas (secondary to tumor necrosis)
may show caval involvement (= unresectable)
| Prognosis: |
60% resectable; 75% mortality; better prognosis than hepatoma; better prognosis for epithelial type than mixed type |
| DDx: |
hemangioendothelioma (fine granular calcifications), metastatic neuroblastoma, mesenchymal hamartoma, hepatocellular carcinoma (>5 years of age, no calcifications) |
Hepatocellular Carcinoma
| Incidence: |
(a) in industrialized world: 0.2–0.8%
(b) in sub-Saharan Africa, Southeast Asia, Japan, Greece, Italy: 5.5–20% |
| Peak age: |
(a) industrialized world: 6th–7th decade; M:F = 2.5:1; fibrolamellar subtype (in 3–10%) below age 40 years
(b) high incidence areas: 30–40 years; M:F = 5:1
(c) in children: >5 years of age (peak at 12–14 years); M:F = 4:3 |
Etiology:
| mnemonic: |
WHAT causes HCC? |
Wilson disease
Hemochromatosis
Alpha-1-antitrypsin deficiency
Tyrosinosis
Hepatitis
Cirrhosis (alcoholic, biliary, cardiac)
Carcinogens (aflatoxin, sex hormones, thorotrast)
| Path: |
soft tumor due to lack of stroma, often hemorrhagic + necrotic |
| Histo: |
HCC cells resemble hepatocytes in appearance + structural pattern (trabecular, pseudoglandular = acinar, compact, scirrhous);
(a) expansive encapsulated HCC: collapsed portal vein branches at capsule
(b) infiltrative nonencapsulated HCC: portal venules communicate with tumoral sinusoids = often invasion of portal ± hepatic veins |
Growth pattern:
-
solitary massive (27–50–59%):
-
multifocal small nodular (15–25%):
-
diffuse microscopic infiltrating form (10–15–26%):
| Vascular supply: |
hepatic artery, portal vein in 6% |
α -fetoprotein elevated in 75–90% (DDx: negative α-fetoprotein in cholangiocarcinoma)
elevated liver function tests
persistent RUQ pain, hepatomegaly, ascites
fever, weight loss, malaise
-
Paraneoplastic syndromes:
| Metastases to: |
lung (most common = 8%), adrenal, lymph nodes, bone |
portal vein invasion (25–33–48%)
arterioportal shunting (4–63%)
invasion of hepatic vein (16%)/IVC (= Budd-Chiari syndrome)
occasionally invasion of bile ducts
calcifications in ordinary HCC (2–9–25%); however, common in fibrolamellar (30–40%) and sclerosing HCC
hepatomegaly and ascites
tumor fatty metamorphosis (2–17%)
CT (sensitivity of 63% in cirrhosis, 80% without cirrhosis):
-
hypodense mass/rarely isodense/hyperdense in fatty liver:
dominant mass with satellite nodules
mosaic pattern = multiple nodular areas with differing attenuation on CECT (up to 63%)
diffusely infiltrating neoplasm
encapsulated HCC = circular zone of radiolucency surrounding the mass (12–32–67%)
| False-positive: |
confluent fibrosis, regenerative nodule |
Biphasic CECT:
enhancement during hepatic arterial phase (80%)
decreased attenuation during portal venous phase with inhomogeneous areas of contrast accumulation
isodensity on delayed scans (10%)
thin contrast-enhancing capsule (50%) due to rapid washout
wedge-shaped areas of decreased attenuation (segmental/lobar perfusion defects due portal vein occlusion by tumor thrombus)
CT with intraarterial ethiodol injection:
hyperdense mass detectable as small as 0.5 cm US (86–99% sensitivity, 90–93% specificity, 50–94% accuracy)
US:
-
variable echogenicity:
hyperechoic HCC (13%) due to fatty metamorphosis or marked dilatation of sinusoids
hypoechoic HCC (26%) due to solid tumor
HCC of mixed echogenicity (61%) due to nonliquefactive tumor necrosis
Doppler peak velocity signals >250 cm/sec
calcifications (rare)
MR:
hypointense (50%)/iso- to hyperintense (with fatty metamorphosis) on T1WI
ring sign = well-defined hypointense capsule on T1WI (24–44%), double layer of inner hypointensity (fibrous tissue) + outer hyperintensity (compressed blood vessels + bile ducts) on T2WI in expansive type of HCC
moderately hyperintense on T2WI
may contain central scar of fibrosis/calcifications/necrosis hypointense on T1WI + T2WI
CEMR:
Gd-DTPA enhancement peripherally (21%)/centrally (7%)/mixed (10%)/no enhancement (21%)
central scar without much enhancement
improved lesion detectability after intravenous administration of superparamagnetic iron oxide
NUC:
Sulfur colloid scan: single cold spot (70%), multiple defects (15-20%), heterogeneous distribution (10%)
Tc-HIDA scan: cold spot/atypical uptake in 4% (delayed images)
Gallium-scan: avid accumulation in 70-90% (in 63% greater, in 25% equal, in 12% less uptake than liver)
Angio:
“thread and streaks” = linear parallel vascular channels coursing along portal venous radicles seen with portal venous involvement
in differentiated HCC: enlarged arterial feeders, coarse neovascularity, vascular lakes, dense tumor stain, arterioportal shunts
in anaplastic HCC: vascular encasement, fine neovascularity, displacement of vessels + corkscrew-like vessels of cirrhosis
| Prognosis: |
>90% overall mortality; 17% resectability rate; 6 months average survival time; 30% 5-year survival time |
| Cx: |
spontaneous rupture (in 8%) |
| Rx: |
(1) Resection
(2) I-131 antiferritin IgG (remission rate >40% up to 3 years) |
| DDx: |
hepatocarcinoma, cholangiocarcinoma, focal nodular hyperplasia, hemangioma, hepatic adenoma |
Fibrolamellar Carcinoma of Liver
| Prevalence: |
1-9% of all HCCs; up to 35% of hCCs in patients <50 years of age |
| Age: |
5-69 (mean 23) years; mostly 2nd-3rd decade; M:F = 1:1 |
| Path: |
large well-circumscribed lobulated nonencapsulated strikingly desmoplastic tumor with calcifications + fibrous central scar |
| Histo: |
large hepatocyte-like cells with granular eosinophilic cytoplasm growing in sheets/cords/trabeculae separated by broad bands of fibrous stroma arranged in parallel lamellae resulting in compartmentalized appearance |
| Risk factors: |
NONE known; underlying cirrhosis or hepatitis in <5% |
| Demographics: |
less common in Europe; rare in Japan + China |
• pain, cachexia; palpable RUQ mass, hepatomegaly
• gynecomastia (rare) from conversion of androgens to estrogens by tumor-elaborated enzyme aromatase
• jaundice (5%) from biliary compression
• alpha;-fetoprotein usually negative/mildly elevated to <200 ng/μL (in up to 10%)
• transaminase levels <100 IU/L
-
partially/completely encapsulated solitary mass (in 80-90%):
intrahepatic (80%)/pedunculated (20%)
5-20 (mean 13) cm in diameter
prominent central fibrous scar (45-60%)
capsular retraction (10%)
punctate/nodular/stellate calcifications located within scar (33-55%)
intratumoral hemorrhage + necrosis (10%)
vascular invasion (<5%)
mass + small peripheral satellite lesions (10-15%)
diffuse multifocal masses (<1%)
regional adenopathy (50–70%): porta hepatis
distant metastases (20%): lung, peritoneal implants
US:
mixed echogenicity (60%)
central hyperechoic scar (33–60%)
CT:
mass of low attenuation
-
enhancement of non-scar portion:
prominent heterogeneous enhancement in arterial + portal venous phase
less pronounced enhancement during equilibrium phase
delayed enhancement of scar (25%) + pseudocapsule of compressed liver tissue (15%)
MRI:
-
large lobulated mass
-
T1WI:
hypointense (86%)/isointense (14%)
homogeneous (80%)/heterogeneous (20%)
-
T2WI:
hyperintense/heterogeneous (85%)
isointense/homogeneous (15%)
hypointense central scar on T1WI + T2WI
Angio:
dense tumor stain
enlarged feeding arteries
NO arteriovenous/arterioportal shunting
avascular central scar
NUC:
photopenic defect on sulfur colloid scan
increased activity during arterial phase + photo-penic during delayed imaging on labeled RBC scan
| Prognosis: |
48% resectability rate; 32 months average survival time; 67% 5-year survival time |
| DDx: |
focal nodular hyperplasia (young + middle-aged women, <5 cm in size, calcifications uncommon, isointense to liver on all CT + MR images with pronounced homogeneous enhancement during arterial phase, hyperintense central scar on T2WI, uptake of sulfur colloid/super paramagnetic iron oxide) |
Hyperplastic Cholecystosis
| Incidence: |
30–50% of all cholecystectomy specimens; M:F = 1:6 |
Adenomyomatosis of Gallbladder
| Histo: |
hyperplasia of epithelial + muscular elements with mucosal outpouching of epithelium-lined cystic spaces into (46%) or all the way through (30%) a thickened muscular layer as tubules/crypts/2–8 mm saccules (= intramural diverticula = Rokitansky-Aschoff sinus); develop with increasing age
[Karl Rokitansky (1804–1878), pathologist in Vienna, Austria]
[Carl Aschoff (1866–1942), pathologist in Bonn, Germany] |
| Incidence: |
2–5% of all cholecystectomy specimens |
| Age: |
>35 years; M:F = 1:3 |
| Associated with: |
(1) Gallstones in 25–75%
(2) Cholesterolosis in 33% |
Types:
| DDx: |
gallbladder carcinoma |
Cholesterolosis
Strawberry Gallbladder
| Associated with: |
cholesterol stones in 50–70% |
Cholesterol Polyp (90%)
| Prevalence: |
4%; most common (50%) fixed filling defect of gallbladder |
| Age: |
40–50 years; M:F=1:3 |
| Location: |
commonly in middle 1/3 of gallbladder |
multiple (on average 8) small filling defects <10 mm (rarely up to 20 mm) in diameter
| DDx: |
papilloma, adenoma, inflammatory granuloma |
Inspissated Bile Syndrome
| Associated with: |
massive hemolysis (Rh incompatibility), hemorrhage (intraabdominal, intracranial, retroperitoneal), increased enterohepatic circulation (Hirschsprung disease, intestinal atresia, stenosis) |
US:
sludge in gallbladder
sludge within bile ducts + partial/complete obstruction (affected ducts may blend with surrounding hepatic parenchyma)
Intraductal Papillary Mucinous Tumor Of Pancreas
= IPMT = MUCINOUS DUCTAL ECTASIA = DUCTECTATIC MUCINOUS CYSTIC TUMOR OF PANCREAS = INTRADUCTAL MUCIN-HYPERSECRETING NEOPLASM = MUCIN-PRODUCING PANCREATIC TUMOR = MUCINOUS VILLOUS ADENOMATOSIS
= rare intraductal tumor originating from papillary epithelial lining typified by voluminous mucin secretions
| Path: |
conglomeration of communicating cysts covered by a rim of normal pancreatic parenchyma + thin fibrous capsule |
| Histo: |
cysts represent a dilated duct lined with innumerable papillae coated with hyperplastic/atypical/malignant epithelium (adenoma-carcinoma sequence) |
| Age: |
elderly patients; M>F |
-
• recurrent episodes of dull pain/acute pancreatitis (due to impaired outflow of pancreatic secretions):
viscosity of fluid greater than normal serum (89% sensitive, 100% specific)
| Prognosis: |
low-grade malignancy with better prognosis than pancreatic adenocarcinoma |
| Dx: |
ERCP (bulging ampulla, mucin pouring from papilla, communication between pancreatic duct + cystic cavity) |
| Rx: |
Whipple operation (main duct IPMT/partial pancreatectomy (branch duct IPMT) |
| DDx: |
chronic obstructive pancreatitis, serous/mucinous cystic tumors, pseudocyst |
Main Duct IPMT
| Age: |
57 (range, 34–75) years; M:F = 1:1 |
hyperechoic, hyperdense, T2-hypointense filling defect within dilated duct (= enhancing papillary mural nodule/gravity-dependent mucin glob)
-
dilatation of main pancreatic duct:
| DDx: |
peripheral mucinous cystic tumor (main duct almost always normal) |
ERCP:
| N.B.: |
reflux of contrast material due to excess of mucin/patent papillary orifice hinders filling of ductal tree |
Branch Duct IPMT
| Age: |
63 (range, 37–76) years; M:F=1:1 |
| Location: |
mainly in uncinate process >> pancreatic tail > pancreatic body |
| Path: |
macrocystic/microcystic pattern; malignancy suggested by irregular thick wall + septa and solid nodules |
-
round/ovoid small lobulated intraductal mass (frequently not visualized):
dilated main pancreatic duct
-
normal main pancreatic duct (almost always normal in small tumor)
Secretin administration distends ducts and enhances detection of communication with main pancreatic duct!
uni-/multilocular cyst 10-20 mm large with sparse septa
| DDx: |
mucinous cystadenoma (no communication with main pancreatic duct); pseudocyst (no intraluminal filling defects) |
multiple thin septa separating fluid-filled lacunae
| DDx: |
serous cystadenoma (no communication with main pancreatic duct) |
± severe pancreatic atrophy
protrusion of papilla into duodenum
ERCP:
contrast spills from main duct into cystically dilated branch ducts
elongated band-/threadlike or nodular filling defects in dilated ducts (= depiction of mucin)
| Cx: |
seeding to main pancreatic duct resulting in main duct IPMT |
Lipoma of Liver
Extremely rare
• asymptomatic
| May be associated with: |
tuberous sclerosis |
| Size: |
few mm–13 cm |
US:
echogenic mass
striking acoustic refraction (sound velocity in soft tissue 1,540 m/sec, in fat 1,450 m/sec)
| Prognosis: |
no malignant potential |
Liver Transplant
Indication:
–chronic viral hepatitis: chronic active hepatitis (4% in childhood)
–metabolic disease: alpha-1 antitrypsin deficiency (9% in childhood), hemochromatosis, Wilson disease
–cholestatic liver disease: primary biliary cirrhosis, primary sclerosing cholangitis, biliary atresia (52% in childhood)
–autoimmune hepatitis
–cryptogenic cirrhosis (6% in childhood)
–alcoholic liver disease
–acute fulminant hepatic failure (11% in childhood): viral hepatitis, drug-induced hepatitis (eg, by acetaminophen, isoniazid), hepatotoxins (eg, mushrooms)
| Contraindications: |
AIDS, extrahepatic malignant tumors, active IVDA/alcohol abuse |
Normal posttransplant findings
-
Periportal edema (21%)
| Cause: |
lymphedema in early posttransplantation period (= dilatation of lymphatic channels due to lack of normal lymphatic drainage) |
“periportal collar” of low attenuation on CT + hyperechogenicity on US
resolution within weeks to months
Fluid collection around falciform ligament (11%), at vascular anastomoses (liver hilum, IVC), biliary anastomosis, lesser sac
Small right pleural effusion
Peri-/subhepatic hematoma/free intraabdominal fluid
Vascular Complications in Liver Transplant (9%)
Most frequent cause of graft loss
• liver failure, bile leak, abdominal bleeding, septicemia
-
1. Anastomotic narrowing of IVC/portal vein
-
2. Thrombosis/stenosis of portal vein (1–3%)
| Cause: |
faulty surgical technique, vessel misalignment, differences in vessel caliber creating turbulent flow, hypercoagulable state, prior portal vein surgery, prior thrombosis in recipient portal vein |
| Rx: |
percutaneous transluminal angioplasty ± stent placement, surgical thrombectomy, venous jump graft, creation of portosystemic shunt, retransplantation |
-
3. Thrombosis/stenosis of IVC (<1%)
-
4. Hepatic artery stenosis (5–13%)
| Location: |
at/near anastomotic site |
| Time of onset: |
within 3 months |
marked focal increase in velocity >200–300 cm/sec + poststenotic turbulence (in >50% stenosis)
intrahepatic tardus et parvus waveform = slowed systolic acceleration time (SAT >0.08 sec) distal to stenosis (73% sensitive)
-
diminished pulsatility (RI <0.5) due to ischemia
| DDx: |
normal in early post-transplantation period |
biliary dilatation (due to stricture), infarction, biloma
| Rx: |
revascularization surgery, balloon angioplasty |
-
5. hepatic artery thrombosis (3–9–16% in adults, 9–19–42% in children)
| Risk factors: |
significant caliber difference between donor + recipient artery, preexisting celiac artery stenosis, prolonged cold ischemia of donor liver, ABo blood type incompatibility, rejection |
| Time of onset: |
usually within first 2 months |
-
6. hepatic artery pseudoaneurysm (uncommon)
| Location: |
at vascular anastomosis |
| Cx: |
massive intraperitoneal hemorrhage, portal vein fistula, biliary fistula |
| Rx: |
surgical resection, embolization, exclusion by stent placement |
Parenchymal Complications in Liver Transplant
-
Rejection
Can ONLY be diagnosed with liver biopsy!
-
Infarction (10%)
may calcify
may liquefy developing into intrahepatic biloma
Graft infection
Biliary Complications in Liver Transplant (6-34%)
Second most common cause of liver dysfunction after rejection
| Time of onset: |
within first 3 months |
-
Biliary obstruction
-
anastomotic stricture (extrahepatic)
| Cause: |
iatrogenic trauma resulting in ischemia + scar formation |
-
nonanastomotic (intrahepatic) stricture
| Cause: |
hepatic arterial thrombosis/stenosis (in 50%), prolonged preservation time, bacterial/viral cholangitis, rejection, recurrent primary sclerosing cholangitis, cholangiocarcinoma, kinking of redundant CBD, sphincter of oddi dysfunction |
-
tension mucocele of allograft cystic duct remnant
| Cause: |
ligation of cystic duct proximally + distally |
extrinsic mass compressing ChD
fluid collection adjacent to ChD
| Cx: |
ascending cholangitis |
-
Bile leak
T-tube exit site: 50% within 10 days
anastomosis of choledochocholedochostomy: 70% within 1st month
-
bile duct necrosis (hepatic artery occlusion)
The intrahepatic biliary epithelium is perfused solely by the hepatic artery!
after liver biopsy
common hepatic duct leak
-
Stone/sludge formation
| Cause: |
alteration in bile composition |
Lymphoma of liver
Pattern:
infiltrative diffuse (most common): no alteration in hepatic architecture
focal nodular: detectable by cross-sectional imaging
combination of diffuse + nodular (3%)
| Detection rate (for CT, MRI): |
<10% |
Mesenchymal Hamartoma Of Liver
| Histo: |
disordered arrangement of primitive fluid-filled mesenchyme, bile ducts, hepatic parenchyma; stromal/cystic predominance with cysts of a few mm up to 14 cm in size; no capsule |
| Age peak: |
15–24 months (range from newborn to 19 years); M:F = 2:1 |
| Location: |
right lobe:left lobe = 6:1; 20% pedunculated |
grossly discernible cysts in 80%
US:
multiple rounded cystic areas on an echogenic background
may appear solidly echogenic in fetus/younger infant (with microcysts creating innumerable tissue-fluid interfaces)
CT:
multiple lucencies of variable size + attenuation (depending on composition of stromal versus cystic elements)
hemorrhage (rare)
enhancement of stromal component
MR:
varying signal intensity (varying concentrations of protein in cystic predominance type)/hypointense on T1WI (mesenchymal predominance type)
marked hyperintensity of cystic locules/hypointense fibrosis on T2WI
NUC:
one/more areas of diminished uptake on sulfur colloid scan
Angio:
hypovascular mass
may show patchy areas of neovascularity
enlarged irregular tortuous feeding vessels
Metastases To Gallbladder
| Organ of origin: |
melanoma, renal cell carcinoma (late in course of disease), lymphoma (in AIDS), malignant fibrous histiocytoma |
| –in children: |
embryonal cell sarcoma, rhabdomyosarcoma |
Metastases To Liver
Most common malignant lesion of the liver
| Incidence: |
the liver is the most common metastatic site after regional lymph nodes; incidence of metastatic carcinoma is 20 × greater than primary carcinoma; metastases represent 22% of all liver tumors in patients with known malignancy |
| Organ of origin: |
colon (42%), stomach (23%), pancreas (21%), breast (14%), lung (13%) |
involvement of liver + spleen typical in leukemia/lymphoma + melanoma
| in children: |
neuroblastoma, Wilms tumor |
| Location: |
both lobes (77%), right lobe (20%), left lobe (3%) |
| Number: |
multiple (50–98%), solitary (2%) |
| Size: |
>33% smaller than 2 cm |
Enhancement characteristics compared with normal liver:
lesion enhancement during arterial phase (metastases are supplied by hepatic artery)
less enhancement during portal venous phase (metastases have a negligible portal venous supply)
extracellular space agents accumulate more in tumor tissue (metastases have a larger interstitial space)
| NUC: |
80–95% sensitivity in lesions >1.5 cm;
lesions <1.5 cm are frequently missed; sensitivity increases with metastatic deposit size, peripheral location, and use of SPECT |
| NECT: |
important for hypervascular tumors (eg, renal cell carcinoma, carcinoid, islet cell tumors), which may be obscured by CECT |
CECT:
Technique:
CT-Angiography (most sensitive imaging modality):
| Indication: |
patients with potentially resectable isolated liver metastases/preoperative to partial hepatectomy for detection of additional metastases (additional lesions detected in 40–55%) |
CT arteriography = angiography catheter in hepatic artery, detects lesions by virtue of increased enhancement
CT arterial portography = angiography catheter in SMA, detects hypodense lesions on a background of increased enhancement of normal surroundings in portal venous phase
CT-delayed iodine scanning:
| Rx: |
Exclusion criteria for metastasectomy:
(1) advanced stage of primary tumor
(2) >4 metastases
(3) extrahepatic disease
(4) <30% normal liver tissue/function available after resection |
Calcified Liver Metastases
Mucinous carcinoma of GI tract (colon, rectum, stomach)
Endocrine pancreatic carcinoma
Leiomyosarcoma, osteosarcoma
Malignant melanoma
Papillary serous ovarian cystadenocarcinoma
Lymphoma
Pleural mesothelioma
Neuroblastoma
Breast cancer
Medullary carcinoma of the thyroid
Renal cell carcinoma
Lung carcinoma
Testicular carcinoma
| mnemonic for mucinous adenocarcinoma: |
COBS |
Colon carcinoma
Ovarian carcinoma
Breast carcinoma
Stomach carcinoma
Hypervascular Liver Metastases
Carcinoid
Hypernephroma
Islet cell carcinoma
Melanoma
Pheochromocytoma
Hypovascular Liver Metastases
Stomach
Colon
Pancreas
Lung
Breast
Hemorrhagic Liver Metastases
Colon carcinoma
Thyroid carcinoma
Breast carcinoma
Choriocarcinoma
Melanoma
Renal cell carcinoma
Echogenic Liver Metastases
Liver Metastases of Mixed Echogenicity
Breast cancer 31%
Rectal cancer 20%
Lung cancer 17%
Stomach cancer 14%
Anaplastic cancer 11%
Cervical cancer 5%
Carcinoid 1%
Echopenic Liver Metastases
Lymphoma 44%
Pancreas 36%
Cervical cancer 20%
Lung (adenocarcinoma)
Nasopharyngeal cancer
Metastases To Pancreas
| Frequency: |
3–10% (autopsy) |
| Organ of origin: |
renal cell carcinoma (30%), bronchogenic carcinoma (23%), breast carcinoma (12%), soft-tissue sarcoma (8%), colonic carcinoma (6%), melanoma (6%) |
solitary (78%)/multiple (17%) ovoid masses with discrete smooth margins
diffuse pancreatic enlargement (5%)
CECT:
heterogeneously (60%)/homogeneously (17%) hyperattenuating relative to pancreas
hypoattenuating relative to pancreas (20%)
isoattenuating relative to pancreas (5%)
Concomitant intraabdominal metastases to:
| DDx: |
ductal pancreatic adenocarcinoma (uniformly nonenhancing mass, encasement of vessels) |
Milk Of Calcium Bile
= LIMY BILE = CALCIUM SOAP
= precipitation of particulate material with high concentration of calcium carbonate, calcium phosphate, calcium bilirubinate
| Associated with: |
chronic cholecystitis + gallstone obstruction of cystic duct |
diffuse opacification of GB lumen with dependent layering
usually functionless GB on oral cholecystogram
US:
intermediate features between sludge + gallstones
Mirizzi Syndrome
| Frequently associated with: |
formation of fistula between gallbladder and common hepatic duct |
• jaundice
cystic duct course usually parallel to CHD
normal CBD below level of impacted stone
-
TRIAD:
gallstone impacted in GB neck
dilatation of bile ducts above level of cystic duct
smooth curved segmental stenosis of CHD
Cholangiography:
partial obstruction of CHD due to external compression on lateral side of duct/eroding stone
| DDx: |
lymphadenopathy, neoplasm of GB/CHD |
Mucinous cystic neoplasm
| Frequency: |
10% of pancreatic cysts; 1% of pancreatic neoplasms |
| Mean age: |
50 years (range of 20–95 years); in 50% between 40–60 years; M:F = 1:9 |
| Path: |
large smooth round/lobulated multiloculated cystic mass encapsulated by a layer of fibrous connective tissue |
| Histo: |
similar to biliary and ovarian mucinous tumors; cysts lined by tall columnar, mucin-producing cells subtended by a densely cellular mesenchymal stroma (reminiscent of ovarian stroma), often in papillary arrangement, lack of cellular glycogen
(a) mucinous cystadenoma
(b) mucinous cystadenocarcinoma = stratified papillary epithelium |
 |
| Intraductal Papillary Mucinous Tumor (IPMT) |
All mucinous cystic neoplasms should be considered as low-grade malignant neoplasms
asymptomatic
abdominal pain, anorexia
| Location: |
often in pancreatic tail (90%)/body, infrequently in head |
well-demarcated thick-walled mass of 2–36 (mean, 10–12) cm in diameter
-
multi-/unilocular large cysts >2 cm with thin septa <2 mm:
A tumor with <6 cysts of >2 cm in diameter is in 93–95% a mucinous cystic neoplasm!
solid papillary excrescences protrude into the interior of tumor (sign of malignancy)
amorphous discontinuous
peripheral mural calcifications (10–15%)
hypovascular mass with sparse neovascularity
vascular encasement and splenic vein occlusion may be present
great propensity for invasion of adjacent organs
US:
cysts may contain low-level echoes
CT:
internal septations may not be visualized without contrast enhancement
cysts with attenuation values of water; may have different levels of attenuation within different cystic cavities
enhancement of cyst walls
Angio:
predominantly avascular mass
cyst wall + solid components may demonstrate small areas of vascular blush + neovascularity
displacement of surrounding arteries + veins by cysts
Metastases:
round thick-walled cystic lesions in liver
| Prognosis: |
invariable transformation into cystadenocarcinoma; 17-63% 5-year survival rate |
| Rx: |
complete surgical excision (5-year survival rate of 74-90%) |
DDx:
Pseudocyst (most common pancreatic cyst): inflammatory changes in peripancreatic fat, pancreatic calcifications, temporal evolution, history of alcoholism, elevated levels of amylase
Lymphangioma/hemangioma
-
Variants of ductal adenocarcinoma:
mucinous colloid adenocarcinoma/ductectatic mucinous tumor of pancreas = mucin-hypersecreting carcinoma
papillary intraductal adenocarcinoma
adenosquamous carcinoma: squamous component predisposes to necrosis + cystic degeneration
anaplastic adenocarcinoma: lymphadenopathy + metastases at time of presentation
Solid and cystic papillary epithelioid neoplasm: hemorrhagic cystic changes in 20%
Cystic islet cell tumor: hypervascular component
Cystic metastases: history of malignant disease
Atypical serous cystadenoma: smaller tumor with greater number of smaller cysts
Sarcoma
Infection: amebiasis, Echinococcus multilocularis
 |
Mirizzi Syndrome |
Multiple Bile Duct Hamartomas
| Incidence: |
0.15-2.8% of autopsies |
| Etiology: |
failure of involution of embryonic bile ducts |
| Histo: |
cluster of proliferated bile ducts lined by single layer of cuboidal cells embedded in fibrocollagenous tissue with single ramified lumen, communication with biliary system usually obliterated |
| Associated with: |
fibropolycystic liver disease |
| Size: |
0.1-10 mm |
• asymptomatic
nonspecific imaging appearance
CT:
multiple scattered round/irregular hypodense lesions of up to 15 mm in diameter
rim of little peripheral/no enhancement
US:
multiple small cysts/echogenic areas (if size not resolved) up to 10 mm ± comet-tail artifact
MR:
hypointense on T1WI
iso-/slightly hyperintense on T2WI
hypointense after gadopentetate dimeglumine
Angio:
multiple areas of abnormal vascularity in form of small grapelike clusters persisting into venous phase
DDx:
Metastatic liver disease (more variable in size and attenuation/signal intensity)
Simple hepatic cysts (not as numerous or uniformly small)
Autosomal dominant polycystic disease (cysts usually larger and more numerous)
Multiple Endocrine Neoplasia
| Theory: |
cells of involved principal organs originate from neural crest and produce polypeptide hormones in cytoplasmic granules, which allow amine precursor uptake and d ecarboxylation = APUD cells |
| |
|
reminder: |
| Type 1 |
= Wermer syndrome |
PPP |
| Type 2 |
= Sipple syndrome (type 2A) |
PMP |
| Type 3 |
= Mucosal neuroma syndrome (type 2B) |
MPM |
MEN 1 Syndrome
| Cause: |
genetic defect on chromosome 11 |
Organ involvement (PPP):
-
Parathyroid hyperplasia (97%): multiglandular
-
Pancreatic islet cell tumor (30–80%):
Likely multiple + behaving malignant!
Primary cause of morbidity + mortality!
-
gastrinoma (most common type, in 50–60%)
-
insulinoma (in 30%)
coexistence with gastrinomas in 10%
VIPoma = WDHH-syndrome (watery diarrhea, hypokalemia, hypochlorhydria)
-
Anterior pituitary gland tumor (15–30–50%):
Combination of parathyroid + pancreas + pituitary involvement (40%)
-
Adrenocortical hyperplasia/adenomas (up to 33–40%)
-
Carcinoid (2–5%)
| Location: |
thymus, bronchus, stomach (30-fold increased incidence), duodenum |
Lipoma
May be associated with:
thyroid tumor (20%), thymoma, buccal mucosal tumor, colonic polyposis, Ménétrier disease
| Screening population: |
<35-year old patient with HPT, ≥2 endocrine organ tumors, 1st-degree relative of MEN 1 patient |
Imaging surveillance:
| Types of Multiple Endocrine Neoplasia |
| MEA |
Type 1 |
Type 2 |
Type 3 |
| Pituitary adenoma |
+ |
| Parathyroid adenoma |
+ |
+ |
| Medullary thyroid carcinoma |
+ |
+ |
| Pancreatic island cell tumor |
+ |
| Pheochromocytoma |
+ |
+ |
| Ganglioneuromatosis |
+ |
MEN 2 Syndrome
| Cause: |
genetic defect on chromosome 10 |
Organ involvement (PMP):
-
Parathyroid hyperplasia/neoplasia in multiple glands
-
Medullary carcinoma of thyroid (almost 100%)
Pheochromocytoma (50%): bilateral in 50%; malignant in 3% diagnosed before (in 10%)/after detection (in 17%) of medullary thyroid carcinoma
| May be associated with: |
carcinoid tumors, Cushing disease |
| Screening population: |
all patients with medullary thyroid cancer/pheochromocytoma, 1st-degree relative of MEN 2 patient |
Imaging surveillance:
MEN 3 Syndrome
Organ involvement (MPM):
long slender extremities (marfanoid appearance)
thickened lips (due to submucosal nodules)
nodular deformity of tongue (mucosal neuromas of tongue often initially diagnosed by dentists)
prognathism
corneal limbus thickening
constipation alternating with diarrhea
-
@ GI tract
thickened/plaquelike colonic wall
chronic megacolon = dilated colon with abnormal haustral markings
alternating areas of colonic spasm + dilatation (rarely associated with Hirschsprung disease)
multiple submucosal neuromas throughout small bowel, may act as lead point for intussusception
Pancreas Divisum
| Prevalence: |
4–9–14% in autopsy series; 2–8% in ERCP series; 3–7% in normal population; 12–26% in patients with idiopathic recurrent pancreatitis |
| Hypothesis: |
relative/actual functional stenosis of minor papilla predisposes to nonalcoholic recurrent pancreatitis in dorsal segment |
| Age: |
young/middle-aged adult |
Pancreatography:
The ONLY reliable means for diagnosis
contrast injection into major papilla demonstrates CBD + only short ventral pancreatic duct with early arborization
contrast injection into minor papilla fills dorsal pancreatic duct
no communication between ventral + dorsal ducts
CT:
oblique fat cleft between ventral + dorsal pancreas (25%)
failure to see union of dorsal + ventral pancreatic ducts (rare)
Pancreatic Acinar Cell Carcinoma
| Age: |
40–81 (mean 62) years; M:F = 86:14; 87% Caucasian |
• increased serum lipase ± amylase
-
• syndrome of elevated lipase:
• biliary obstruction distinctly uncommon
lobulated well-defined mass of 2–15 cm in diameter
thin enhancing capsule
tumor necrosis usually present
moderately vascular tumor + neovascularity + arterial and venous encasement
| Prognosis: |
median survival of 7–9 months |
| DDx: |
(1) pancreatic adenocarcinoma (small, irregular, locally invasive, without capsule, biliary obstruction if located in head of pancreas)
(2) Nonfunctioning islet-cell tumor
(3) Microcystic cystadenoma
(4) Solid and papillary epithelial neoplasm (5) Oncocytic tumor of pancreas |
Pancreatic Ductal Adenocarcinoma
| Incidence: |
95% of malignant tumors of pancreas; 5th leading cause of cancer death in the United States (27,000 per year) |
| Etiology: |
alcohol abuse (4%), diabetes (2 × more frequent than in general population, particularly in females), hereditary pancreatitis (in 40%); cigarette smoking (risk factor 2 x) |
| Path: |
scirrhous infiltrative adenocarcinoma with a dense cellularity + sparse vascularity |
| Peak age: |
7th (range, 4th–8th) decade; M:F = 2:1 |
| Stage |
I = confined to pancreas
II = + regional lymph node metastases
III = + distant spread |
-
At presentation:
65% of patients have advanced local disease/distant metastases
21% of patients have localized disease with spread to regional lymph nodes
14% of patients have tumor confined to pancreas
Extension:
local extension beyond margins of organ (68%): posteriorly (96%), anteriorly (30%), into porta hepatis (15%), into splenic hilum (13%)
-
invasion of adjacent organs (42%):
-
local lymph node spread:
| Metastases: |
liver (30–36%), regional lymph nodes >2 cm (15–28%), ascites from peritoneal carcinomatosis (7–10%), lungs (pulmonary nodules/lymphangitic), pleura, bone |
• weight loss, anorexia, fatigue
• pain in hypochondrium radiating to back
-
• obstructive jaundice (75%):
• acute onset diabetes (25–50%), steatorrhea
• hyperamylasemia
• spontaneous vein thrombosis (Trousseau syndrome)
| Location: |
pancreatic head (60%); body (15%); tail (5%); diffuse involvement (20%) |
| Size: |
2–10 cm (in 60% between 4–6 cm) |
UGI:
“antral pad sign” = extrinsic indentation of the posteroinferior margin of antrum
“Frostberg inverted-3” sign = inverted 3 contour to the medial portion of the duodenal sweep
spiculated duodenal wall + traction + fixation (neoplastic infiltration of duodenal mucosa/desmoplastic response)
irregular/smooth nodular mass with ampullary carcinoma
BE:
diffuse tethering throughout peritoneal cavity (from intraperitoneal seeding)
localized haustral padding/flattening/narrowing with serrated contour at inferior aspect of transverse colon/splenic flexure
CT (75–96% detection rate for dynamic CT scan):
hypovascular lesion best depicted during parenchymal/portal venous phase (11% not visualized)
pancreatic mass (95%)/diffuse enlargement (4%)/normal scan (1%)
mass with central zone of diminished attenuation (75–83%)
-
indirect signs:
convex deformity of pancreatic contour
“double-duct sign” = pancreatic + bile duct obstruction without detectable mass (4%)
duct dilatation (58%): 3/4 biductal, 1/10 isolated to one duct; dilated pancreatic duct (67%); dilated bile ducts (38%)
atrophy of pancreatic body + tail (20%)
calcifications (2%)
postobstructive pseudocyst (11%)
obliteration of peripancreatic fat (50%) = pancreas lacks a capsule
-
vascular invasion:
thickening of celiac axis/SMA (invasion of perivascular lymphatics) in 60%
dilated collateral veins (12%)
high probability of unresectability if circumferential contiguity of tumor to vessel >50% (84% sensitive, 98% specific)
thickening of Gerota fascia (5%)
local tumor extension posteriorly, into splenic hilum, into porta hepatis (68%)
contiguous organ invasion (duodenum, stomach, mesenteric root) in 42%
hepatic metastases (75% sensitive)
US:
hypoechoic pancreatic mass
focal/diffuse (10%) enlargement of pancreas
contour deformity of gland; rounding of uncinate process
dilatation of pancreatic ± biliary duct
MR (no diagnostic improvement over CT; valuable in evaluation of an enlarged pancreatic head):
hypointense lesion on T1WI (accentuated on fat-suppressed images)
hypovascular lesion during capillary phase compared with surrounding pancreas (due to desmoplastic fibrotic component)
lesion enhancement >1 minute after contrast injection (due to desmoplasia with large interstitial spaces)
abnormally low signal intensity of pancreatic tail + body (due to atrophy/secondary chronic pancreatitis) on T1WI reducing the contrast relative to focal cancer
Angiography (70% accuracy):
hypovascular tumor/neovascularity (50%)
arterial encasement: SMA (33%), splenic artery (14%), celiac trunk (11%), hepatic artery (11%), gastroduodenal artery (3%), left renal artery (0.6%)
venous obstruction: splenic vein (34%), SMV (10%)
venous encasement: SMV (23%), splenic vein (15%), portal vein (4%)
Cholangiography:
“rat tail/nipplelike” occlusion of CBD
nodular mass/meniscuslike occlusion in ampullary tumors
double duct sign = abrupt obstruction of common bile + pancreatic duct
Pancreatography (abnormal in 97%):
irregular, nodular, rat-tailed, eccentric obstruction
localized encasement with prestenotic dilatation
acinar defect
Prognosis:
10% 1-year survival, 2% 3-year survival, <1% 5-year survival; 14 months medial survival after curative resection, 8 months after palliative resection, 5 months without treatment; tumors resectable in only 8-15% at presentation, 5% 5-year survival rate after surgery
Survival rate & tumor size:
| DDx: |
focal pancreatitis, islet cell carcinoma, metastasis, lymphoma, normal variant |
Pancreatic Islet Cell TUmors
| Origin: |
embryonic neuroectoderm, derivatives of APUD (amine precursor uptake and decarboxylation) cell line arising from islet of Langerhans (APUDoma) |
| Prevalence: |
1-5:1,000,000 population/year; isolated or part of MEN I syndrome (= Wermer syndrome) |
| Path: |
(a) small tumor: solid well-demarcated
(b) large tumor: cystic changes + necrosis + calcifications |
| In order of frequency: |
insulinoma > gastrinoma > glucagonoma > VIPoma > somatostatinoma |
| Histo: |
sheets of small round cells + numerous stromal vessels |
Average time from onset of symptoms to diagnosis is 2.7 years
Classification:
| Metastases: |
in 60-90% to liver ± regional lymph nodes |
Liver metastasis often hypervascular with enhancement during arterial phase
hyperechoic liver metastasis is suggestive of islet cell tumor rather than pancreatic adenocarcinoma!
marked enhancement on immediate images (hypervascularity)
marked enhancement on delayed images (large interstitial space with loose edematous stroma + abundant blood vessels)
No vascular encasement/duct obstruction
calcifications + large size highly suggestive of malignancy
US:
transabdominal US (70% sensitive)
endoscopic US (nearly 95% sensitive, 93% specific), less sensitive for distal pancreatic body + tail
intraoperative US (combined with palpation by surgeon)
homogeneous hypoechoic mass
CT (71-82% sensitive)
Tumors often small (<20 mm) and multiple + difficult to detect
isoattenuating tumor at NECT
avid enhancement in arterial phase
tumor may be cystic/hypoattenuating (rare)
MR:
low signal intensity on T1WI
high signal intensity on moderately T2WI
intense enhancement on arterial-phase postcontrast images
hypervascular liver metastases
NUC (70–90% sensitive, only 50% sensitive for gastrinomas + insulinomas)
Hepatic venous sampling (88% sensitive):
performed together with pancreatic angiography
rise in venous hormone concentration after selective injection of secretagogue (eg, calcium) into arteries supplying the pancreas
| Prognosis: |
50% 5-year survival rate |
| DDx: |
(1) Pancreatic ductal adenocarcinoma (hypovascular, smaller, encasement of SMA + celiac trunk)
(2) Microcystic adenoma (benign tumor, small cysts, older women)
(3) Metastatic tumor: renal cell carcinoma (clinical Hx)
(4) Solid and papillary epithelial neoplasm (young female, hemorrhagic areas)
(5) Paraganglioma (6) Sarcoma (rare) |
ACTH-producing Tumor
= Corticotrophinoma
rare cause of Cushing syndrome
• increased level of serum cortisol
• impaired glucose tolerance > central obesity > hypertension, oligomenorrhea > osteoporosis > purpura > striae > muscle atrophy
| Prognosis: |
almost all malignant with metastases at time of diagnosis |
Gastrinoma
2nd most common islet cell tumor
| Age: |
8% in patients <20 years; M > F |
| Histo: |
in αcells/δ cells |
| Path: |
(a) islet cell hyperplasia (10%)
(b) benign adenoma (30%): in 50% solitary, in 50% multiple (especially in MEN 1)
(c) malignant (50–60%) with metastases to liver, spleen, lymph nodes, bone |
| Associated with: |
MEN 1 (in 50–60%); the most common islet cell tumor in MEN 1 |
-
• Zollinger-Ellison syndrome: severe recurrent peptic ulcer disease (>90%), malabsorption, hypokalemia, gastric hypersecretion, hyperacidity/occasionally hypoacidity, diarrhea (from gastric hypersecretion)
Only 1:1,000 patients with peptic ulcer disease has a gastrinoma!
• epigastric pain (recurrent/intractable peptic ulcer disease)
• GI bleeding
-
• elevated serum levels of gastrin (DIAGNOSTIC)
| Location: |
usually multiple |
ulcer in unusual location, eg, postbulbar
average tumor size 3.4 cm (up to 15 cm)
occasionally calcifications
homogeneous hypoechoic mass
Angio:
hypervascular lesion (70%)
hepatic venous sampling after intraarterial stimulation with secretin
CT:
transiently hyperdense on dynamic CT (majority)
thickening of gastric rugal folds
MR:
low-intensity mass on fat-suppressed T1WI
diminished central + peripheral ring enhancement
high-intensity mass on fat-suppressed T2WI
Sensitivity of preoperative localization:
25% for US, 35% for CT, 20% for MRI, 42–63% for transhepatic portal venous sampling for gastrin, 68–70% for selective angiography, 77% for arteriography combined with intra-arterial injection of secretin
| Rx: |
surgery curative in 30% |
| Cx: |
frequently malignant degeneration (liver metastases at time of diagnosis in 30%) |
Glucagonoma
| Incidence: |
uncommon tumor |
| Age: |
middle age; M < F |
| Histo: |
derived from α± cells |
| Associated with: |
MEN |
• necrolytic erythema migrans (erythematous macules/papules on genitals, lower extremity, groin, buttocks, face) in >70% of patients
• 4D syndrome = dermatosis, diarrhea, depression, deep vein thrombosis
• painful glossitis/stomatitis, weight loss, anemia
• plasma glucagon level > 1,000 ng/L (DIAGNOSTIC);
± diabetes mellitus due to elevated glucagon
-
• ± elevation of insulin, serotonin, gastrin
| Location: |
predominantly in pancreatic body/tail |
tumor size 2.5–25 cm (mean 6.4 cm) with solid + necrotic components (in 70% >5 cm in size)
hypervascular in 90%; successful angiographic localization in 15%
| Cx: |
deep vein thrombosis + pulmonary embolism |
| Prognosis: |
in 60–80% malignant transformation (liver metastases at time of diagnosis in 50–60%); 55% 5-year survival rate |
Insulinoma
Most common syndromic islet cell tumor!
| Age: |
4th–6th decade; M:F = 2:3 |
| Associated with: |
MEN type I (in 10%) |
| Path: |
(a) single benign adenoma (80–90%)
(b) multiple adenomas/microadenomatosis (5–10%)
(c) islet cell hyperplasia (5–10%)
(d) malignant adenoma (5–10%) |
• Whipple triad: starvation attack + hypoglycemia (fasting glucose <50 mg/dL) + relief by IV dextrose
• elevated levels of plasma insulin
• neuroglycopenic symptoms: headaches, confusion, coma
• hypoglycemia exacerbated by fasting results in frequent meals to avoid symptoms
• sweating, palpitations, tremor (secondary to catecholamine release in response to hypoglycemia)
• obesity
-
• firm rubbery palpable mass at surgery (in >90%)
| Location: |
no predilection for any part of pancreas,
2–5% in ectopic location; 10% multiple |
| memonic: |
10% are associated with MEN 1;
10% are multiple (especially in MEN 1)
10% have islet cell hyperplasia;
10% are malignant |
average tumor size 1–2 cm; <1.5 cm in 70%
US (20–75% preoperative and 75–100% endoscopic + intraoperative sensitivity):
round/oval smoothly marginated solid homogeneously hypoechoic mass
Angio:
hypervascular tumor (66%): accurate angiographic localization in 50–90%
transhepatic portal venous sampling (correct localization in 95%)
hepatic venous sampling after intraarterial stimulation with calcium gluconate
CECT (30–75% sensitivity):
hypo-/iso-/hyperattenuating lesion
MR:
low signal intensity on fat-suppressed T1WI
hyperintense on T2WI + dynamic contrast-enhanced + suppressed inversion recovery images
tumors >2 cm show ring enhancement
| Prognosis: |
malignant transformation in 5–10% |
| Rx: |
surgery curative |
Nonfunctioning Islet Cell Tumor
= Nonsyndromic ICT
3rd most common islet cell tumor!
| Incidence: |
15–25–50% of all islet cell tumors |
| Histo: |
derived from either α or βcells |
| Age: |
24–74 (mean 57) years |
mostly asymptomatic (= tumors may be hormonally active but without clinical evidence of hormone production)
abdominal pain, jaundice, gastric variceal bleeding
palpable mass, gastric outlet obstruction
| Location: |
predominantly in pancreatic head |
tumor size 6–20 cm (>5 cm in 72%) with solid + necrotic components
coarse nodular calcifications (20–25%)
CT contrast enhancement in 83%
hypoechoic mass
late dense capillary stain
large irregular pathologic vessels with early venous filling
| Prognosis: |
in 80–100% malignant transformation with metastases to liver + regional nodes; 60% 3-year survival; 44% 5-year survival |
| Rx: |
may respond to systemic chemotherapy |
Somatostatinoma
| Origin: |
derived from δ cells |
| Incidence: |
fewer than 200 cases reported in literature |
| May be associated with: |
NF 1 |
• inhibitory syndrome = inhibitory action of somatostatin on other pancreatic + bowel peptides (growth hormone, TSH, insulin, glucagon, gastric acid, pepsin, secretin)
• diabetes, cholelithiasis, steatorrhea, hypochlorhydria
-
• elevated plasma level of somatostatin (DIAGNOSTIC)
| Location: |
predominantly in pancreatic head/duodenum at ampulla of Vater |
tumor size 0.6–20 cm (average >4 cm)
hypervascular
obstruction of duodenum
| Prognosis: |
50–90% malignant transformation; metastatic disease to liver/lymph nodes in 50–70% at time of initial diagnosis |
VIPoma
| Histo: |
adenoma/hyperplasia; M:F = 1:2 |
-
• WDHA syndrome = watery diarrhea + hypokalemia + achlorhydria (VIP inhibits gastrin poroduction);
• WDHH syndrome = watery diarrhea + hypokalemia + hypochlorhydria = “pancreatic cholera” = Verner-Morrison syndrome
• dehydration due to massive diarrhea (>1 L/day)
Location:
pancreas: from δ cells predominantly in pancreatic body/tail (75%)
extrapancreatic: retroperitoneal ganglioblastoma, pheochromocytoma, lung, neuroblastoma (in children)
average size 5–10 cm with solid + necrotic tissue
mostly hypervascular tumor
dilatation of gallbladder
| Prognosis: |
in 50–80% malignant transformation |
| DDx: |
small cell carcinoma of lung/neuroblastoma may also cause WDHH syndrome |
Pancreatic Lipomatosis
Predisposing factors:
Atherosclerosis of elderly
Obesity
Steroid therapy
Diabetes mellitus
Cushing syndrome
Chronic pancreatitis
Main pancreatic duct obstruction
Cystic fibrosis (most common cause in childhood)
Malnutrition/dietary deficiency
Hepatic disease
Hemochromatosis
Viral infection
Schwachman-Diamond syndrome
Johanson-Blizzard syndrome
-
fatty replacement often uneven:
increase in AP diameter of pancreatic head with focal fatty replacement = lipomatous pseudohypertrophy
prominently lobulated external contour
US:
increased pancreatic echogenicity
CT:
“marbling” of pancreatic parenchyma/total fatty replacement/lipomatous pseudohypertrophy
Pancreatic Fatty Sparing
| Histo: |
ventral pancreatic anlage has smaller + more densely packed acini with scanty/absent interacinar fat |
US:
rounded/triangular hypoechoic area within pancreatic head/uncinate process + diffusely increased echogenicity in remainder of gland
CT:
higher-density region of pancreatic head + uncinate process with diffusely decreased attenuation of pancreatic body + tail
Pancreatic Pseudocyst
| Etiology: |
(1) Acute pancreatitis; requires >4 weeks to form; pseudocysts mature in 6–8 weeks
(2) Chronic pancreatitis
(3) Posttraumatic
(4) Pancreatic cancer |
| Incidence: |
2–4% in acute pancreatitis;
10–15% in chronic pancreatitis |
| Location: |
2/3 within pancreas |
Atypical location (may dissect along tissue planes in 1/3):
intraperitoneal: mesentery of small bowel/transverse colon/sigmoid colon
retroperitoneal: along psoas muscle; may present as groin mass/in scrotum
intraparenchymal: liver, spleen, kidney
mediastinal (through esophageal hiatus > aortic hiatus > foramen of Morgagni > erosion through diaphragm): may present as neck mass
| May communicate with: |
duodenum, stomach, spleen |
Plain film/contrast radiograph:
smooth extrinsic indentation of posterior wall of stomach/inner duodenal sweep (80%)
indentation/displacement of splenic flexure/transverse colon (40%)
downward displacement of duodenojejunal junction
gastric outlet obstruction
splaying of renal collecting system/ureteral obstruction
US (pseudocyst detectable in 50-92%; 92-96% accuracy):
usually single + unilocular cyst
multilocular in 6%
fluid-debris level/internal echoes (may contain sequester, blood clot, cellular debris from autolysis)
septations (rare; sign of infection/hemorrhage)
may increase in size (secondary to hypertonicity of fluid, communication with pancreatic duct, hemorrhage, erosion of vessel)
obstruction of pancreatic duct/CBD
CT:
fluid in pseudocyst (0-30 HU)
cyst wall calcification (extremely rare)
Pancreatography:
communication with pancreatic duct in up to 50-70%
Indications for pseudocyst drainage:
pain, suspected infection, persistence of pseudocyst >5 cm, increasing size, biliary/gastrointestinal obstruction
Cx (in 40%):
Rupture into abdominal cavity, stomach, colon, duodenum
hemorrhage/formation of pseudoaneurysm
-
Infection = pancreatic abscess
| Dx: |
transcutaneous needle aspiration |
Intestinal obstruction
| Prognosis: |
spontaneous resolution (in 20–50%) secondary to rupture into GI tract/pancreatic/bile duct |
| DDx: |
pancreatic cystadenoma, cystadenocarcinoma, necrotic pancreatic carcinoma, fluid-filled bowel loop, fluid-filled stomach, duodenal diverticulum, aneurysm |
Pancreatic Transplantation
| Complications: |
sepsis, rejection, pancreatitis, pseudocyst, pancreatic abscess (22%), anastomotic leak |
| Prognosis: |
40% survival rate >1 year |
Graft-vessel thrombosis in pancreatic transplant (2-19%)
Acute Rejection of Pancreatic Transplant
focal tenderness over transplant
measurement of urinary + serum amylase, blood glucose (nonspecific for diagnosis of rejection)
US:
poor margination of transplant
acoustic inhomogeneity
dilated pancreatic duct
 |
| Pancreatic Transplantation |
Pancreatitis
Cause:
Theories of pathogenesis:
reflux of bile/pancreatic enzymes/duodenal succus
(a) terminal duct segment shared by common bile duct + pancreatic duct
(b) obstruction at papilla of Vater from inflammatory stenosis, edema/spasm of sphincter of Oddi, tumor, periduodenal diverticulum
(c) incompetent sphincter of Oddi
Acute Pancreatitis
Path:
INTERSTITIAL EDEMATOUS PANCREATITIS (75–95%): edema, congestion, leukocytic infiltrates; mortality rate of 4%
-
NECROTIZING PANCREATITIS (5–25%):
proteolytic destruction of pancreatic parenchyma; mortality rate of 80–90%
-
(a) HEMORRHAGIC PANCREATITIS:
(b) SUPPURATIVE PANCREATITIS:+ bacterial infection
Clinical stages:
-
I = EDEMATOUS PANCREATITIS (75%)
-
II = PARTIALLY NECROTIZING PANCREATITIS
-
III = TOTALLY NECROTIZING PANCREATITIS
| Mortality: |
100% (40% by 2nd day, 75% by 5th day, 100% by 10th day) |
acute epigastric pain radiating to back/chest (peaking after a few hours, resolving in 2–3 days)
nausea, vomiting
raised pancreatic amylase + lipase in blood + urine
increased amylase-creatinine clearance ratio
-
signs of hemorrhagic pancreatitis:
Cullen sign = periumbilical ecchymosis
Grey-Turner sign = flank ecchymosis
Fox sign = infrainguinal ecchymosis
subcutaneous nodules + fat necrosis + polyarthritis
Distribution:
NO findings on US/CT in 29%
Abdominal film:
“colon cutoff” sign (2–52%) = dilated transverse colon with abrupt change to a gasless descending colon (inflammation via phrenicocolic ligament causes spasm + obstruction at the splenic flexure impinging on a paralytic transverse colon)
“sentinel loop” (10–55%) = localized segment of gas-containing bowel in duodenum (in 20–45%)/terminal ileum/cecum
“renal halo” sign = water-density of inflammation in anterior pararenal space contrasts with perirenal fat; more common on left side
mottled appearance of peripancreatic area (secondary to fat necrosis in pancreatic bed, mesentery, omentum)
intrapancreatic gas bubbles (from acute gangrene/suppurative pancreatitis)
“gasless abdomen” = fluid-filled bowel associated with vomiting
ascites
CXR (findings in 14–71%):
pleural effusion (in 10–20%), usually left-sided, with elevated amylase levels (in 85%)
left-sided diaphragmatic elevation
left-sided subsegmental atelectasis (20%)
parenchymal infiltrates, pulmonary infarction
pulmonary edema, ARDS
pleural empyema, pericardial effusion
mediastinal abscess, mediastinal pseudocyst
pancreatico-bronchial/-pleural/-pulmonary fistula
UGI:
esophagogastric varices (from splenic vein obstruction)
enlarged tortuous edematous rugal folds along antrum + greater curvature (20%)
widening of retrogastric space (from pancreatic enlargement/inflammation in lesser sac)
diminished duodenal peristalsis + edematous folds
widening of duodenal sweep + downward displacement of ligament of Treitz
Poppel sign = edematous swelling of papilla
Frostberg inverted-3 sign = segmental narrowing with fold thickening of duodenum
jejunal + ileal fold thickening (proteolytic spread along mesentery)
BE:
narrowing, nodularity, fold distortion along inferior haustral row of transverse colon ± descending colon
Cholangiography:
long gently tapered narrowing of CBD
prestenotic biliary dilatation
smooth/irregular mucosal surface
Bone films (findings in 6%):
| Cause: |
metastatic intramedullary lipolysis + fat necrosis + trabecular bone destruction |
| Time of onset: |
usually 3–6 weeks after peak of clinical pancreatitis |
punched out/permeative mottled destruction of cancellous bone + endosteal erosion
aseptic necrosis of femoral/humeral heads
metaphyseal infarcts, predominantly in distal femur + proximal tibia
US (pancreatic visualization in 62–78%):
hypoechoic diffuse/focal enlargement of pancreas
dilatation of pancreatic duct (if head focally involved)
perivascular cloaking = spread of inflammatory exudate along perivascular spaces
extrapancreatic hypoechoic mass with good acoustic transmission (= phlegmonous pancreatitis)
-
fluid collection: lesser sac (60%), L > R anterior pararenal space (54%), posterior pararenal space (18%), around left lobe of liver (16%), in spleen (9%), mediastinum (3%), iliac fossa, along transverse mesocolon/mesenteric leaves of small intestine
pseudocyst formation (52%): extension into lesser sac, transverse mesocolon, around kidney, mediastinum, lower quadrants of abdomen
CT (pancreatic visualization in 98%):
no detectable change in size/appearance (29%)
-
enlargement of pancreas with convex margins + indistinctness of gland + parenchymal heterogeneity:
hypodense (5–20 HU) mass in
phlegmonous pancreatitis; may persist long after complete recovery
hyperdense areas (50–70 HU) in
hemorrhagic pancreatitis for 24–48 hours
thickening of anterior pararenal fascia
“halo sign” = sparing of perirenal space
non–contrast-enhancing parenchyma during bolus injection (= pancreatic necrosis)
fluid collection
Angiography:
may be normal
hypovascular areas (15–56%)
hypervascularity + increased parenchymal stain (12–45%)
venous compression secondary to edema
formation of pseudoaneurysms (in 10% with chronic pancreatitis): splenic artery (50%), pancreatic arcades, gastroduodenal artery
Cx:
Phlegmon (18%)
Pseudocyst formation (10%)
Hemorrhagic pancreatitis (2–5%)
Abscess (2–10%)
Pancreatic ascites
Biliary duct obstruction
Thrombosis of splenic vein/SMV
-
Pseudoaneurysm
| Incidence: |
in up to 10% of severe pancreatitis |
| Location: |
splenic artery (most common), gastroduodenal, pancreatico-duodenal, hepatic, left gastric artery |
| Mortality: |
37% for rupture, 16–50% for surgery |
-
Thoracopancreatic fistula
pancreaticopleural fistula
pancreaticopericardial fistula
pancreaticoesophageal fistula
pancreaticobronchial fistula
mediastinal pseudocyst
Rx:
Conservative (NPO, gastric tube, atropine, analge-sics, sedation, prophylactic antibiotics) for stage I
Early surgery in stages II and III
Mild Acute Pancreatitis (75%)
| Path: |
interstitial edema |
| Prognosis: |
improvement within 48–72 hours following conservative therapy with gradual decrease of elevated enzymes |
| Mortality: |
1–5% |
Severe Acute Pancreatitis
| Associated with: |
organ failure/local complications |
| Path: |
pancreatic cell breakdown + necrosis |
| Cx: |
acute fluid collection, pancreatic necrosis, pseudocyst, abscess |
Acute Fluid Collections (30–50%)
| Path: |
lack of a defined wall of fibrous/granulation tissue; pancreatic phlegmon [misnomer, no infection] = solid boggy inflammatory mass characterized by edema, infiltration of inflammatory cells + necrosis of retroperitoneal fat |
| Location: |
extension into lesser sac, anterior pararenal space, transverse mesocolon, small bowel mesentery, retroperitoneum, pelvis |
near 0 HU on CT
| Prognosis: |
spontaneous regression (in 40–50%) |
Pancreatic Necrosis
| Path: |
clumps of devitalized pancreatic parenchyma + hemorrhage in pancreatic and peripancreatic tissues |
| Histo: |
extensive interstitial fat necrosis with vessel damage + necrosis of acinar cells, islet cells, ductal system |
| Associated with: |
peripancreatic fat necrosis |
focal/diffuse well-marginated zones of unenhanced pancreatic parenchyma > 3 cm/involving >30% of the pancreatic gland
Acute Pseudocyst
| Path: |
absence of epithelium-lined wall |
| Cause: |
acute pancreatitis, pancreatic trauma, chronic pancreatitis |
| Time of onset: |
>4 weeks after acute pancreatitis |
| Prognosis: |
persistent pseudocyst usually communicates with pancreatic duct; spontaneous resolution in 44%; <4 cm: resolution anticipated; >7 cm: treatment recommended |
| Cx: |
hemorrhage, infection; spontaneous rupture into hollow viscera |
PANCREATIC ABSCESS
| Time of onset: |
2-4 weeks after severe acute pancreatitis |
| Organism: |
most commonly due to E. coli |
Chronic Pancreatitis
| Incidence: |
4:100,000 (in Western countries) |
Etiology:
Plain film:
numerous irregular calcifications (in 20–50% of alcoholic pancreatitis) PAThoGNoMoNIC
UGI:
displacement of stomach/duodenum by pseudocyst
shrinkage/fold induration of stomach (DDx: linitis plastica)
stricture of duodenum
Cholangiopancreatography (most sensitive imaging modality):
side-branch ectasia = slight ductal ectasia/clubbing of side branches (minimal disease)
“nipping” = narrowing of the origins of side branches
dilatation >2 mm, tortuosity, wall rigidity, main ductal stenosis (moderate disease)
“beading, chain of lakes, string of pearls” = multifocal dilatation, stenosis, obstruction of main pancreatic duct + side branches (severe disease)
intraductal filling defects due to mucinous protein plugs/calculi/debris
prolonged emptying of contrast material
may have stenosis/obstruction + prestenotic dilatation of CBD
filling of pseudocysts (<50%)
US/CT:
irregular (73%)/smooth (15%)/beaded (12%) pancreatic ductal dilatation (in 41-68%)
small atrophic pancreas (in 10-54%)
pancreatic calcifications (4–50–68%)
inhomogeneous gland with increased echogenicity (62%)
irregular pancreatic contour (45–60%)
focal (12–32%)/diffuse (27–45%) pancreatic enlargement during flare up (DDx: pancreatic carcinoma)
mostly mild biliary ductal dilatation (29%)
intra-/peripancreatic pseudocysts (20–34%)
segmental portal hypertension (= splenic vein thrombosis + splenomegaly) in 11%
arterial pseudoaneurysm formation
peripancreatic fascial thickening + blurring of organ margins (16%)
ascites/pleural effusion (9%)
no abnormalities (7%)
MR:
loss of signal intensity on fat-suppressed T1WI (from loss of aqueous protein in pancreatic acini secondary to fibrosis)
diminished heterogeneous contrast enhancement (from loss of normal capillary network replaced by fibrous tissue)
Angiography:
increased tortuosity + angulation of pancreatic arcades + intrahepatic arteries (88%)
luminal irregularities/focal fibrotic arterial stenoses (25–75%)/smooth beaded appearance
irregular parenchymal stain
venous compression/occlusion (20–50%)
portoportal shunting + gastric varices without esophageal varices
| Cx: |
pancreatic carcinoma (2–4%), jaundice, pseudocyst formation, pancreatic ascites, thrombosis of splenic/mesenteric/portal vein |
| Rx: |
surgery for infected pseudocyst, GI bleeding from portal hypertension, common bile duct obstruction, gastrointestinal obstruction |
| DDx: |
pancreatic carcinoma (extrapancreatic spread) |
Chronic Alcoholic Pancreatitis
Chronic Obstructive Pancreatitis
Etiology:
Congenital/acquired lesions of pancreatic duct
Trauma/surgical duct ligation
Sphincter of Oddi dysfunction, ampullary stenosis
Primary sclerosing cholangitis
Idiopathic fibrosing pancreatitis
Renal failure
Slow growing ampullary tumor
dilatation of main pancreatic duct
normal sized/focally or diffusely enlarged/small atrophic gland
calcifications uncommon
Nonalcoholic Duct-Destructive Chronic Pancreatitis
| Location: |
body + tail of pancreas |
focal/diffuse enlargement with decreased attenuation
narrow main pancreatic duct without irregularities
no calcifications
MR:
homogeneously decreased signal intensity on T1WI isointense relative to spleen
variable intensity on T2WI
Papillary Adenoma Of Bile Ducts
| Path: |
usually solitary tumor/papillomatosis with papillary fronds extending into lumen |
| Histo: |
columnar epithelium supported by connective tissue from lamina propria |
| Location: |
common bile duct > right/left hepatic duct |
usually small intraductal mass
visualized at cross-sectional imaging only if large enough
| Prognosis: |
high rate of recurrence after surgical resection |
| Cx: |
malignant transformation (rare) |
Passive Hepatic Congestion
| Cause: |
CHF, constrictive pericarditis |
| Pathophysiology: |
chronic central venous hypertension transmitted to hepatic sinusoids results in centrilobular congestion + eventually hepatic atrophy, necrosis, fibrosis |
CT:
globally delayed enhancement (36%)
enhancement of portal veins + hepatic arteries + immediately adjacent parenchyma (56%)
“reticulated mosaic” pattern = lobular patchy areas of enhancement separated by coarse linear regions of diminished attenuation (100%)
diminished periportal attenuation (24%)
diminished attenuation around intrahepatic IVC (8%)
prominent IVC + hepatic vein enhancement (due to contrast reflux from right atrium into dilated IVC)
| DDx: |
Budd-Chiari syndrome (regional/lobular distribution of reticulated mosaic pattern, caudate lobe hypertrophy) |
Peliosis
[pelios, Greek = purple]
| Cause: |
(a)? acquired: chronic infection (disseminated TB), hepatotoxic drugs (androgen-anabolic steroids, corticosteroids, tamoxifen citrate, chemotherapeutic agents, azathioprine, oral contraceptives, thorium dioxide injection), diabetes mellitus, chronic renal failure, advanced malignancy (Hodgkin disease, myeloma, disseminated cancer)
(b) bacillary peliosis hepatis in AIDS (lesions contain bacilli of Rochalimaea species) responsive to antibiotics
(c)? congenital: angiomatous malformation |
| Histo: |
(1) Phlebectatic peliosis hepatis (early stage)
= endothelial-lined cysts (=? dilatation of central veins) communicating with dilated hepatic sinusoids + compression of surrounding liver
(2) Parenchymal peliosis hepatis (late stage)
= irregularly shaped cysts without lining communicating with dilated hepatic sinusoids + areas of liver cell necrosis |
| Associated with: |
hormonally induced benign/malignant tumors |
| Location: |
liver (most common), spleen, bone marrow, lymph nodes, lungs) |
| Age: |
fetal life (rare) to adult life |
• incidental discovery
hepatomegaly, splenomegaly
US:
multiple indistinct areas of hypo-/hyperechogenicity
CECT:
initially hypoattenuating, with passage of time isoattenuating/enhancing round lesions
MR:
mixed signal intensity due to repeated hemorrhage (deoxyhemoglobin + methemoglobin + siderotic nodules)
Angio:
multiple small (several mm to 1.5 cm) round collections of contrast medium scattered throughout liver in late arterial phase of hepatic arteriogram
± simultaneous opacification of hepatic veins
| Prognosis: |
reversible after drug withdrawal/progression to hepatic failure/intraperitoneal hemorrhage leading to death |
Porcelain Gallbladder
| Incidence: |
0.6–0.8% of cholecystectomy patients; M:F = 1:5 |
| Histo: |
(a) flakes of dystrophic calcium within chronically inflamed + fibrotic muscular wall
(b) microliths scattered diffusely throughout mucosa, submucosa, glandular spaces, Rokitansky-Aschoff sinuses |
| Associated with: |
gallstones in 90% |
• minimal symptoms
curvilinear (muscularis)/granular (mucosal) calcifications in segment of wall/entire wall
nonfunctioning GB on oral cholecystogram
highly echogenic shadowing curvilinear structure in GB fossa (DDx: stone-filled contracted GB)
echogenic GB wall with little acoustic shadowing (DDx: emphysematous cholecystitis)
scattered irregular clumps of echoes with posterior acoustic shadowing
| Cx: |
10–20% develop carcinoma of gallbladder |
Portal Hypertension
Classification:
Pathophysiology:
Flow direction:
hepatopetal (petere, Latin = to seek)
-
hepatofugal (fugere, Latin = to flee) = flow reversal
| Cause: |
intrahepatic arterioportal communications (inside portal triads vasa vasorum of portal veins + hepatic arteries connect via bile duct capillaries to portal vein) |
| Spontaneous Portosystemic Shunts |
| Type of Varices |
Frequency (%) |
| Coronary venous |
80–86 |
| Esophageal |
45–65 |
| Paraumbilical |
10–43 |
| Abdominal wall |
30 |
| Perisplenic |
30 |
| Retrogastric/gastric |
2–27 |
| Paraesophageal |
22 |
| Omental |
20 |
| Retroperitoneal paravertebral |
18 |
| Mesenteric |
10 |
| Splenorenal |
10 |
| Gastrorenal |
7 |
• elevated hepatic wedge pressure (HWP) = portal venous pressure; normal values seen in presinusoidal portal hypertension
• caput medusae = drainage from paraumbilical + omental veins through superficial veins of chest (lateral thoracic vein to axillary vein; superficial epigastric vein to internal mammary vein and subclavian vein) + abdominal wall (circumflex iliac vein and superficial epigastric vein to femoral vein; inferior epigastric vein to external iliac vein)
• hemorrhaging esophageal varices (50%)
-
@ Splanchnic system:
portal vein >13 mm (57% sensitivity, 100% specificity)
SMV + splenic vein >10 mm; coronary vein >4 mm; recanalized umbilical vein >3 mm (size of vessels not related to degree of portal hypertension or presence of collaterals)
loss of respiratory increase of splanchnic vein diameters of <20% (81% sensitive, 100% specific)
portal vein aneurysm
portal vein thrombosis
cavernous transformation of portal vein
increased echogenicity + thickening of portal vein walls
-
Doppler US:
continuous monophasic portal venous flow pattern without respiratory fluctuations
reduction of mean portal vein velocities to 7–12 cm/sec (normally 12–30 cm/sec)
loss of flow increase in portal venous system during expiration
congestive index >0.13 cm/sec (= ratio of area of portal vein divided by flow velocity; 67% sensitive)
may have bidirectional/hepatofugal (<10%) flow within spontaneous splenorenal shunts (indicates high incidence of hepatic encephalopathy)
dilated hepatic artery may demonstrate elevated resistive index >0.78
-
@ Spontaneous portosystemic shunts:
-
connection to SVC
Esophageal varices (= subepithelial + submucosal veins) supplied by anterior branch of left gastric vein
-
Paraesophageal varices (endoscopically not visible) supplied by posterior branch of coronary (= left gastric) vein draining into azygos + hemiazygos vv. + vertebral plexus
NOT connected to esophageal varices!
mediastinal/lung mass on CXR in 5–8%
-
connection to pulmonary circulation
-
retrograde mesenteric flow
-
retroperitoneal collaterals
Splenorenal/splenoadrenorenal shunt
Gastrorenal shunt
Mesenterorenal shunt (between SMV + right renal v.)
Mesenterogonadal shunt (between ileocolic v. + right testicular v.)
Splenocaval shunt (between splenic v. + left hypogastric v.)
intrahepatic shunt (portal v. to hepatic v.)
-
@ Cruveilhier-von Baumgarten syndrome (20–35%)
-
@ Spleen
splenomegaly (absence does not rule out portal hypertension)
-
siderotic Gamna-Gandy nodules in 13% (= small foci of perifollicular + trabecular hemorrhage):
multiple 3–8-mm low-intensity spots on FLASh/GRASS images
multiple hyperechoic spots on US
multiple faint calcifications on CT
ascites
| Cx: |
Acute gastrointestinal bleeding (mortality of 30–50% during 1st bleeding) |
Segmental Portal Hypertension
Portosystemic Surgical Connections
-
NONSELECTIVE SHUNT
-
Portocaval shunt
-
Mesocaval shunt
short “H-graft” to posterior wall of SMV
long “C-graft” to anterior wall of SMV
direct mesocaval shunt dividing IVC (rare)
Mesorenal shunt
-
Mesoatrial shunt
-
SELECTIVE SHUNT
Doppler criteria for shunt patency:
increased local velocities
turbulence + severe spectral broadening
dilatation of recipient vein at shunt site
phasic flow pattern in portal tributaries
hepatofugal flow in intrahepatic portal vein branches
reduction in size + number of portosystemic collaterals
reduction/absence of ascites or splenomegaly
Transjugular Intrahepatic Portosystemic Shunt (TIPS)
| Indication: |
patients with esophageal + gastric variceal hemorrhage/refractory ascites due to advanced liver disease with portal hypertension, hepatorenal syndrome |
| Type of stent: |
10-mm Wall stent (curved), Palmaz stent (straight), Strecker stent, spiral Z stent |
| Shunt surveillance: |
at regular 3–6-month intervals for |
Assessment:
-
MORPHOLOGY
Ascites
Portosystemic collaterals
Size of spleen
Diameter of stent (usually 8–10 mm)
Configuration of stent: areas of narrowing
Extension of stent into portal + hepatic veins
-
HEMODYNAMICS
Direction of flow in: extrahepatic portal vein, R + L portal vein, SMV, splenic vein, all 3 hepatic veins, intrahepatic IVC, paraumbilical vein, coronary vein
Peak blood flow velocity within main portal vein
Peak blood flow velocity within proximal + mid + distal aspects of stent
Hepatic artery: PSV, EDV, RI
high-velocity turbulent flow (50–270 cm/s) at least double that of pre-TIPS values
superimposed cardiac + respiratory variations
increase in hepatic artery velocities from 77 cm/s (pre-TIPS) to 119 cm/s (post-TIPS)
reversed flow direction within portal vein branches
| Cx: |
- Obstruction to flow
- Shunt obstruction (38%)
- Hepatic vein stenosis
- Trauma
- Vascular injury
- Hepatic artery pseudoaneurysm
- Arterioportal fistula
- Intrahepatic/subcapsular hematoma
- Hemoperitoneum (due to penetration of liver capsule)
- Biliary injury
- Transient bile duct dilatation (due to hemobilia)
- Bile collection
- Stent dislodgment with embolization to right atrium, pulmonary artery, internal jugular vein
|
| Mortality: |
<2% (intraperitoneal hemorrhage) |
TIPS failure
| Cause: |
acute thrombosis, improper stent placement, intimal hyperplasia, hepatic vein stenosis, change in stent configuration, bulging of liver parenchyma into shunt |
| Prevalence: |
31% at 1 year, 42% at 2 years |
Pre- and Post-TIPS Baseline Study
(under stable fasting conditions) |
| |
Pre-TIPS |
Post-TIPS |
| Portal vein velocity (cm/s) |
10–30 |
40–60 |
| Mean portal vein velocity (cm/s) |
18 ± 6 |
55 ± 7 |
| Portal pressure (mm hg) |
37 ± 8 |
22 ± 6 |
| Shunt peak velocity (cm/s) |
0 |
95 ± 58 |
Portal Vein Thrombosis
Etiology:
| Age: |
predominantly children, young persons |
Acute Portal Vein Thrombosis
Plain film:
hepatosplenomegaly
enlarged azygos vein
paraspinal varices
UGI:
esophageal varices
thickening of bowel wall
US:
echogenic material within vessel lumen (67%)
increase in portal vein diameter (57%)
portosystemic collateral circulation (48%)
enlargement of thrombosed segment >15 mm (38%)
thickening of lesser omentum
Doppler-US:
-
no flow on postprandial Doppler color scans:
Malignant thrombus tends to distend vein + exhibit pulsatile flow, a bland thrombus does not!
-
decrease in hepatic artery resistive index:
RI <0.50 (in acute occlusive portal vein thrombosis)
minimal decrease/normal RI (in chronic portal vein thrombosis/nonocclusive thrombosis)
NECT:
decreased attenuation of affected hepatic parenchyma (due to edema, depletion of hepatocytes, fibrosis)
CECT:
transient high attenuation during hepatic arterial phase (due to increased arterial flow)
-
low-density center of portal vein thrombus surrounded by peripheral enhancement:
portal vein density 20–30 HU less than aortic density
MR:
absent flow void in portal area + abnormal signal intensity in main portal vein
hyperintense thrombus on T1WI + T2WI (if <5 weeks old)
filling defect on MRA
Angio:
“thread and streaks” sign of tumor thrombus (streaky contrast opacification of tumor vessels)
| Cx: |
(1) Cavernous transformation (19%)
(2) Hepatic infarction
(3) Bowel infarction |
Chronic Portal Vein Thrombosis
Pathophysiology:
nonvisualization of extrahepatic portal vein (= fibrotic portal vein)
calcification within clot/wall of portal vein
-
cavernous transformation (=
cavernoma) of portal vein:
presence of a racemose conglomerate of collateral veins with portal venous flow linking pancreas + duodenum + gallbladder fossa
splenomegaly
ascites
CECT:
peripheral scattered areas of high attenuation in liver during hepatic arterial phase
US:
echogenic/nonvisualized portal vein
MR:
hypointense portal vein on T1WI + hyperintense on T2WI (2–18 months old)
numerous abnormal flow voids in porta hepatis
Postcholecystectomy Syndrome
Incidence:
mild recurrent symptoms in 9–25%; severe symptoms in 2.6–32% (result of 1,930 cholecystectomies):
— completely cured (61%)
-
— satisfactory improvement with
-
— failure with
occasional attacks of severe pain (3%)
continuous severe distress (1.7%)
recurrent cholangitis (0.7%)
Cause:
Richter Syndrome
| Etiology: |
transformation/dedifferentiation of CLL lymphocytes |
| Incidence in CLL patients: |
3–10% |
| Median age: |
59 years |
| Medium time interval after diagnosis of CLL: |
24 months |
fever (65%) without evidence of infection
increasing lymphadenopathy + hepatosplenomegaly (46%)
weight loss (26%), abdominal pain (26%)
| Location: |
bone marrow, lymph nodes, liver, spleen, bowel, lung, pleura, kidney, dura |
| Prognosis: |
median survival time: 4 months from diagnosis of lymphoma; 14% rate of remission rate |
Schistosomiasis
Major cause of portal hypertension worldwide: 200 million people affected
Types:
-
SCHISTOSOMA MANSONI
occurs in >70 million inhabitants of parts of Africa, Caribbean, Arabic peninsula, West Indies, northern part of South America
-
SCHISTOSOMA JAPONICUM
coastal areas of China, Japan, Formosa, Philippines, Celebes
-
SCHISTOSOMA HAEMATOBIUM
Cycle:
cercariae enter lymphatics + blood system via thoracic duct; larvae are transported into mesenteric capillaries; mature in portal system + liver into worms; worms live in pairs in copula within portal vein + tributaries for 10–15 years; female swims against blood flow to reach venules of urinary bladder (S. haematobium) or intestine + rectum (S. mansoni, S. japonicum); deposits eggs in wall of urinary bladder or intestines, eggs pass with urine + feces; hatch within water to release miracidia which infect snail hosts; cercariae emerge after maturation from snails
| Infection: |
cercariae penetrate human skin/buccal mucosa from contaminated water (slow-moving streams, irrigation canals, paddy fields, lakes) |
| Histo: |
granulomatous reaction + fibrosis along portal vein branches |
Schwachman-Diamond Syndrome
= rare probably autosomal recessive condition characterized by congenital absence of pancreatic exocrine tissue
2nd most frequent cause of exocrine pancreatic insufficiency in childhood after cystic fibrosis!
• pancreatic insufficiency, steatorrhea
• recurrent respiratory and skin infections (secondary to bone marrow hypoplasia)
• normal electrolytes in sweat
• failure to thrive
• tends to improve with time
total fatty replacement of pancreas
metaphyseal chondrodysplasia resulting in dwarfism
| DDx: |
cystic fibrosis (pancreatic calcifications, cyst formation, abnormal sweat test) |
Serous Cystadenoma Of Pancreas
| Incidence: |
approximately 50% of all cystic pancreatic neoplasms |
| Histo: |
cyst walls lined by cuboidal/flat glycogen-rich epithelial cells derived from centroacinar cells of pancreas (DDx: lymphangioma), thin fibrous pseudocapsule |
| Age: |
34–88 years; mean age 65 years; 82% over 60 years of age; M:F = 1:2–4 |
| Associated with: |
von Hippel-Lindau syndrome |
pain, weight loss, malaise, anorexia, fatigue, jaundice
palpable mass
| Location: |
any part of pancreas affected, slight predominance for head + neck |
well-demarcated lobulated mass 1–25 (mean 5) cm in diameter with smooth/nodular contour
innumerable small <2 cm cysts of honeycomb/bunch of grapes appearance; uncommonly few large cysts (in <5%)/cyst up to 8 cm in diameter
prominent central stellate scar (ChARACTERISTIC)
amorphous central calcifications (in 18%) in dystrophic area of stellate central scar (“sunburst”)
pancreatic duct + CBD may be displaced, encased, or obstructed
-
US:
solid predominantly echogenic mass with mixed hypoechoic + echogenic areas
-
CT:
attenuation values close to water
contrast enhancement
-
Angio:
hypervascular mass with dilated feeding arteries, dense tumor blush, prominent draining veins, neovascularity, occasional AV shunting, No vascular encasement
-
MR:
delayed enhancement of scar on contrast-enhanced FLASh images
| Prognosis: |
no malignant potential |
| Rx: |
surgical excision/follow-up examinations |
| DDx: |
malignant mucinous cystic neoplasm (younger age, body + tail of pancreas, >10 cm large at presentation) |
Solid And Papillary Neoplasm Of Pancreas
= SOLID AND CYSTIC TUMOR = PAPILLARY-CYSTIC NEOPLASM = SOLID AND PAPILLARY EPITHELIAL NEOPLASM = HAMOUDI TUMOR
= rare, low-grade malignant tumor; often misclassified as nonfunctioning islet cell tumor, cystadenoma, or cystadenocarcinoma of pancreas
| Prevalence: |
0.17–2.7% of all nonendocrine pancreatic tumors |
| Mean age: |
25 (range 10–74) years; M:F = 1:9; especially in black and East Asian patients |
| Path: |
large well-encapsulated mass with considerable hemorrhagic necrosis + cystic degeneration |
| Histo: |
sheets + cords of cells arranged around a fibrovascular stroma |
| Location: |
tail of pancreas (most frequently) |
well-encapsulated inhomogeneous round/lobulated pancreatic mass with solid + cystic portions
may be completely cystic (when complicated by extensive necrosis + internal hemorrhage)
fluid-debris level (20%)
mean diameter of 9 cm (range 3–15 cm)
± stippled/punctate/amorphous dystrophic calcification (33%)
hypovascular with no contrast enhancement/enhancement of solid tissue projecting toward center of mass
-
US:
echogenic mass with necrotic center
-
MR:
high signal intensity on T1WI (consistent with hemorrhagic necrosis)
| Prognosis: |
(1) excellent after excision
(2) metastases (in 4%): omentum, lymph nodes, liver |
| DDx: |
(1) Microcystic adenoma (innumerable tiny cysts, older age group)
(2) Mucinous cystic neoplasm (large uni-/multilocular cysts, older age group)
(3) Nonfunctioning islet cell tumor (hypervascular)
(4) Pleomorphic carcinoma of pancreas (smaller tumor in older patient)
(5) Pancreatoblastoma (childhood tumor)
(6) Calcified hemorrhagic pseudocyst |
Splenic Angiosarcoma
| Incidence: |
rare, <100 cases in literature |
| Cause: |
usually not due to thorotrast or toxic exposure to vinyl chloride/arsenic as in liver angiosarcoma |
| Age: |
50–60 years |
MR:
focal/diffuse hypointense foci on T1WI + T2WI (iron deposition from hemorrhage)
| Prognosis: |
20% survival rate after 6 months |
Splenic Hamartoma
| Etiology: |
congenital |
| May be associated with: |
hamartomas elsewhere as in tuberous sclerosis |
| Histo: |
- mixture of white + red pulp (most common)
- white pulp subtype = aberrant lymphoid tissue
- red pulp subtype = aberrant complex of sinusoids
|
• asymptomatic
-
CT:
attenuation equal to/hypodense to splenic tissue
prolonged heterogeneous enhancement
-
MR:
heterogeneously hyperintense on T2WI
diffuse heterogeneous enhancement, more homogeneous on delayed images
Splenic Hemangioma
| Cause: |
congenital, arising from sinusoidal epithelium |
| Prevalence: |
0.03–14% (autopsy); M > F
♢Most common primary splenic tumor! |
| Age: |
20–50 years |
| Histo: |
proliferation of vascular channels lined by single layer of endothelium; mostly of cavernous type; may contain areas of infarction, hemorrhage, thrombosis, fibrosis |
| Associated with: |
generalized angiomatosis Klippel-Trénaunay-Weber syndrome, Beckwith-Wiedemann syndrome, Turner syndrome |
| Prognosis: |
slow growth, thus becoming symptomatic in adulthood |
| Cx: |
(1) Spontaneous splenic rupture (in up to 25%)
(2) Kasabach-Merritt syndrome (= anemia, thrombocytopenia, coagulopathy) with large hemangioma
(3) Portal hypertension
(4) Malignant degeneration |
Splenic Infarction
Most common cause of focal defects!
-
Cause:
Embolic: bacterial endocarditis (responsible in 50%), atherosclerosis with plaque emboli, cardiac thrombus (atrial fibrillation, left ventricular thrombus), metastatic carcinoma
Local thrombosis: sickle cell disease (leading to functional asplenia), myelo-/lymphoproliferative disorders (CML most common), polycythemia vera, myelofibrosis with myeloid metaplasia + splenomegaly, Gaucher disease, collagen vascular disease, portal hypertension
Vasculitis: periarteritis nodosa
Vascular compromise of splenic artery: focal inflammatory process (eg, pancreatitis), thrombus from splenic artery aneurysm, splenic torsion
Therapeutic complication: transcatheter hepatic arterial embolization
Pancreatic carcinoma, Pancreatitis
Sickle cell disease/trait
Adenocarcinoma of stomach
Leukemia
Mitral stenosis with emboli
Subacute bacterial endocarditis
| Anatomy: |
branches of the splenic artery are noncommunicating end arteries |
| Cx: |
acute febrile illness, abscess formation, pseudocyst formation, splenic rupture, hemorrhage |
Splenosis
= posttraumatic autotransplantation of splenic tissue to other sites (heterotopic splenic tissue)
| Age: |
young men with history of trauma/splenectomy |
| Time of detection: |
mean of 10 years (range of 6 months to 32 years) after trauma |
| Location: |
diaphragmatic surface, liver, greater omentum, small bowel serosa, parietal peritoneum, pleura after diaphragmatic rupture (attaches to peritoneal/pleural surface) |
multiple small encapsulated sessile implants
| Size: |
few mm to 3 cm (due to limited blood supply from local neovascularization) |
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CT:
isodense to normal spleen with homogeneous enhancement
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MR:
hypointense on T1WI
heterogeneous enhancement (red + white pulp differences)
hyperintense/rarely hypointense (due to iron deposition) on T2WI
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NUC:
uptake by Tc-99m sulfur colloid; In-111 labeled platelets; Tc-99m heat-damaged RBC (best detection rate without uptake by liver)
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Significance:
protects against infection in pediatric patients
may be confused with metastases/lymphoma
responsible for disease recurrence after splenectomy (eg, idiopathic thrombocytopenic purpura)
Spontaneous Perforation Of Common Bile Duct
| Pathogenesis: |
unknown (? CBD obstruction, localized mural malformation, ischemia, trauma) |
| Age: |
5 weeks to 3 years of age |
• vague abdominal distension
• mild persistent hyperbilirubinemia
• varying acholic stools
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US:
biliary ascites/loculated subhepatic fluid
localized pseudocholedochal cyst in porta hepatis
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Hepatobiliary scintigraphy:
radioisotope diffusely throughout peritoneal cavity
Thorotrastosis
Thorotrast = 25% colloidal suspension of thorium dioxide; used as contrast agent between late 1920s and mid 1950s, in particular for cerebral angiography and liver spleen imaging; chemically inert with high atomic number of 90; >100,000 people injected
Thorium dioxide = consists of 11 radioactive isotopes (thorium-232 is major isotope); decay by means of alpha, beta, and gamma emission; biologic half-life of 1.34 × 1010 years; hepatic dose of 1,000–3,000 rads in 20 years
| Distribution: |
phagocytized by RES + deposited in liver (70%), spleen (30%), bone marrow, abdominal lymph nodes (20%) |
linear network of metallic density contrast material in spleen, lymph nodes, liver
spleen may be shrunken/nonfunctional
| Cx: |
hepatic fibrosis, angiosarcoma (50%), cholangiocarcinoma, hepatocellular carcinoma (latency period of 3–40 years; mean 26 years) |
Tyrosinemia
= rare autosomal recessive metabolic disorder
| Country: |
increased prevalence in Canadian province of Quebec and parts of Scandinavia |
| Biochemistry: |
deficiency of enzyme fumarylacetoacetase (last step in catabolic pathway of tyrosine, serum methionine, urinary succinylacetone); elevated levels of serum tyrosine as a precursor of dopamine, norepinephrine, epinephrine, melanin, thyroxin |
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ACUTE FORM
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CHRONIC FORM
= Fanconi syndrome with renal tubular dysfunction
•vitamin D-resistant rickets
•intermittent porphyria-like symptoms
• progressive liver failure in early childhood
• anemia, abnormal liver function tests
• elevated levels of α±-fetoprotein
hepatosplenomegaly
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micro- and macronodular cirrhosis (early childhood):
regenerating nodules of 2–20 mm: hyper- (mostly) /iso-/hypoattenuating; hypo-/occasionally hyperechoic
portal hypertension
increased echogenicity (fibrosis + fatty infiltration)
nephromegaly with uniformly thickened renal cortices
nephrocalcinosis
| Prenatal Dx: |
enzyme deficiency demonstrable in hepatocytes, skin fibroblasts, lymphocytes, amniocytes |
| Cx: |
hepatocellular carcinoma (in 37% beyond 2 years of age) |
| Rx: |
(1) Diet restricted in phenylalanine + tyrosine (alleviates kidney damage but does not prevent fatal outcome)
(2) 2-2-nitro-4-trifluoro-methylbenzoyl-1,3-cyclohexanedione (NTBC) inhibits 4-hydroxyphenylpyruvate dioxygenase + prevents formation of maleylacetoacetate and fumarylacetoacetate
(3) Liver transplantation (before HCC develops) |
Undifferentiated Sarcoma Of Liver
| Incidence: |
4th/5th most common liver tumor in pediatric population |
| Age: |
<2 months (in 5%); 6–10 years (in 52%); by 15 years (in 90%); up to 49 years; M:F = 1:1 |
| Histo: |
primitive undifferentiated stellate/spindle-shaped sarcomatous cells closely packed in whorls + sheets/scattered loosely in a myxoid ground substance with foci of hematopoiesis (50%) |
painful RUQ mass and fever
mild anemia + leukocytosis (50%)
elevated liver enzymes (33%)
fever (5%)
| Location: |
right lobe (75%); left lobe (10%);both lobes (15%) |
7–14–21 cm in size
well-defined margins (fibrous pseudocapsule)
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NUC:
photodefect on sulfur colloid scan
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US/CT:
large intrahepatic mass with cystic areas up to 4 cm in diameter (myxoid stroma + necrosis + hemorrhage)
discordant finding between US (solid) + CT (cystlike)
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Angio:
hypo-/hypervascular with stretching of vessels
scattered foci of neovascularity
| Prognosis: |
mostly results in death within 12 months |
| DDx: |
mesenchymal hamartoma
(a) solid lesion + cystic degeneration:
hepatocellular carcinoma, fibrolamellar carcinoma, intrahepatic cholangiocarcinoma, angiosarcoma, epithelioid hemangio-endothelioma, other sarcomas, lymphoma, metastatic disease, hepatocellular adenoma
(b) solitary cystic lesion:
biliary cystadenoma/biliary carcinoma, cystic degeneration of hepatocellular carcinoma, bacterial/parasitic abscess, metastatic disease, posttraumatic resolving hematoma |
Wandering Spleen
| Cause: |
embryologically absent/malformed gastrosplenic + splenorenal ligaments; deficient/lax abdominal musculature (prune-belly syndrome, pregnancy) |
| Age: |
any (higher frequency in women of childbearing age) |
• asymptomatic mobile abdominal/pelvic mass
• chronic vague lower abdominal/back pain
• nausea, vomiting, eructation, flatulence
•acute abdomen (with splenic infarction from torsion)
empty splenic fossa + associated soft-tissue mass in center of abdomen/pelvis
inverted malpositioned stomach
splenic hilum often located anteriorly
displaced large spleen (congestion during torsion)
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Cx:
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Torsion with prolonged venous occlusion: perisplenitis, localized peritonitis, adhesions, venous thrombosis, hypersplenism
no flow within spleen on Doppler US
elevated resistive index in proximal splenic artery
low attenuation with heterogeneous enhancement on CT
whorled appearance of twisted splenic pedicle
Torsion with arterial occlusion: hemorrhagic infarction, subcapsular/intrasplenic hemorrhage, gangrene, degenerative cysts, functional asplenism
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GI complications:
@ Stomach: compression, distension, volvulus, traction diverticulum, varices
@ Small bowel: dilatation, obstruction
@ Colon: compression, volvulus, laxity, ptosis
| Rx: |
1. Splenectomy (4% postsplenectomy sepsis)
2. Splenopexy
3. Conservative treatment (if asymptomatic) |
