Atlas of Mammography
3rd Edition

Chapter 4
Circumscribed Masses
Masses with circumscribed margins are a common finding on mammography. Well-defined lesions are more commonly benign, but it imperative that the radiologist evaluating a mass differentiate those that are characteristically benign from the indeterminate or suspicious lesions. Careful mammographic assessment includes comparison with prior mammography and the use of spot compression to assess the details of the margin of a seemingly circumscribed mass. Sonography (1) plays a key role in the differentiation of solid from cystic masses and greatly facilitates the recommendations for follow-up or further evaluation of the patient.
Assessment of Circumscribed Masses
An approach to the evaluation of a well-defined mass on mammography includes an assessment of the shape, density, margins, size, orientation, presence of a fatty halo, and presence of other findings (i.e., calcifications). Benign lesions tend to be isodense or less dense than the parenchyma and to have very circumscribed margins, whereas malignant masses are more often of greater density and have fine irregularity or micronodularity on their borders.
The shapes of masses that are circumscribed may be round, oval, or lobular. The margination that is described as “circumscribed” allows one to visualize a fine, clear edge around the entire mass. Often masses that are circumscribed may be overlapped by parenchyma in some areas. These are described as obscured or partially circumscribed. A microlobulated margin appears as fine nodularity or undulation of the edge of the lesion and implies a more malignant nature.
A basic division of well-circumscribed masses based on their density is of help in determining possible etiologies of and approach to such lesions. In Table 4.1 the differential diagnosis of circumscribed masses based on their density is shown. Masses that are fatty—lipomas, oil cysts, and galactoceles—and circumscribed masses that are mixed density are characteristically benign. Isodense circumscribed masses include benign and malignant lesions, and an evaluation of the borders is critical to help differentiate these etiologies. Masses that are of high density, particularly for their size, are of concern for malignancies. However, in a study of radiologists’ interpretations of mass density, Jackson et al. (2) found that the assessment of mammographic density of masses was quite variable among different readers; in addition, the density assessment was of limited value in the prediction of benign versus malignant for noncalcified breast masses.
The mammographic feature of greatest importance in assessing a relatively circumscribed isodense mass is its margination. Any notching, waviness, or indistinctness of the margins of a mass should be regarded with suspicion (3). The presence of a halo sign, i.e., a fine radiolucent ring surrounding a well-defined mass, has long been considered to be a mammographic sign of benignancy (4). The halo may be due to compression of fat by the mass (5) or to Mach effect (6). Swann et al. (7) have, however, described 25 malignant lesions from approximately 1,000 breast cancers in which a halo sign was present. The presence of a halo suggests but does not guarantee a benign process (7). Certainly, the presence of a partially circumscribed margin and a partially indistinct margin is suspicious, and biopsy is indicated in this situation.
Stability in size from prior mammography is an important factor that suggests that a circumscribed noncystic mass is benign. The growth rates of breast cancers are quite variable. In two series, the mean doubling times for mammary carcinoma have been found to be 212 (8) and 325 (9) days, respectively. The lack of interval change suggests that a well-defined lesion is more likely benign, but this is not confirmatory. Meyer and Kopans (10) reported five cases of occult cancers that did not change in size on follow-up mammography over a minimum of 2 years and a maximum of 4.5 years from the original study. Therefore, if a nodule is followed and there is no interval change in the size at 6 months or 1 year, continued follow-up is necessary. In addition, the other features of density and margination are used to decide whether to follow or biopsy a circumscribed mass.
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TABLE 4.1 Differential Diagnosis of Circumscribed Masses
Density Type of Lesion Characteristics
Fat-containing masses Hamartoma Encapsulated, large, mixed density
  Lipoma Encapsulated, radiolucent
  Intramammary node Mixed density, small, lateral location, subcutaneous
  Fat necrosis (oil cyst) Radiolucent with eggshell calcification
  Galactocele Fat density or mixed density, lactating patient
Isodense Cyst Round, any size, oriented toward the nipple
  Fibroadenoma Lobulated, any size, coarse calcification
  Tubular adenoma Lobular, noncalcified
  Fibrocystic change Partially circumscribed
  Adenosis tumor May have microcalcification
  Focal fibrosis Partially circumscribed
  Papilloma Small, may calcify, periareolar
  Hematoma Slightly indistinct, skin thickening
  Hemangioma Subcutaneous, small
  Metastases Round, subcutaneous
  Inclusion cyst Round, subcutaneous, may calcify
  Pseudoangiomatous stromal hyperplasia Relatively circumscribed, noncalcified
  Lactating adenoma Pregnant, lactating, lobulated mass
  Skin lesion (neurofibroma, nevus, keratosis) Crenulated surface, extremely well defined (air halo)
  Nipple out of profile Different appearance on orthogonal view
High density Carcinoma Microlobulated or slightly indistinct, microcalcifications
  Cystosarcoma phylloides Very large lobulated, may have coarse calcification
  Abscess Medium to high density, skin thickening
  Hematoma Slightly indistinct, skin thickening
Circumscribed Masses of Fat Density
Lipoma
Lipomas are benign, well-circumscribed radiolucent masses (Figs. 4.1,4.2,4.3,4.4,4.5). Clinically, lipomas are either nonpalpable or, if palpable, soft and freely mobile. Lipomas are visualized more easily in an otherwise dense, glandular breast because of the difference in density. In a fatty breast, this radiolucent mass is perceived because it is surrounded by a thin capsule and, if large, displaces the normal breast around it (11). Often lipomas may be located posteriorly at the chest wall and project forward into the breast. Only the anterior aspect of the capsule may be visible on mammography in these cases. Lipomas may develop coarse calcification, probably secondary to infarction (Fig. 4.6). On ultrasound, lipomas are usually intensely hyperechoic, oval, and well defined.
Fat Necrosis
Posttraumatic oil cysts, a form of fat necrosis, may occur as early as 6 months after breast trauma or surgery. Oil cysts may be evident in a pattern corresponding to the path of the seat belt shoulder restraint in patients who have been in automobile accidents (12). Clinically, an area of fat necrosis may be asymptomatic, or it may be an indurated mass with thickening or retraction of the overlying skin. Histologically, the fat necrosis is characterized by anuclear fat cells, histiocytic giant cells, and foamy phagocytic histiocytes. The necrotic focus may cavitate, forming an oil cyst (13), and the wall of the oil cyst may calcify in an eggshell pattern. This ringlike calcification (Figs. 4.7,4.8,4.9,4.10) in the wall of an oil cyst, as originally described by Leborgne (14), is characteristic of this form of fat necrosis. Extensive oil cysts in the subcutaneous area of the breast and the soft tissues elsewhere are seen in the condition known as steatocystoma multiplex (15) (Fig. 4.11).
Galactoceles
Galactoceles may be radiolucent masses or they may be of mixed density or isodense, depending on their contents. Galactoceles are benign breast masses that contain inspissated milk; they are commonly found during or after lactation (11). Mammographically, they are small, round often multiple, radiolucent or mixed-density lesions, and they often occur in the retroareolar
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area (11). The retention of lactiferous material accounts for the low density of these lesions (16) (Fig. 4.12). A fat-water level within a well-defined mass on a mediolateral view is pathognomonic of a galactocele (17) (Fig. 4.13).
Figure 4.1 HISTORY: A 52-year-old woman with a positive family history of breast cancer for screening mammography.
MAMMOGRAPHY: Bilateral MLO (A) and coned left MLO (B) views show an oval circumscribed radiolucent mass (arrows) in the left breast posteriorly. A thin capsule surrounds the mass, which is characteristic of a lipoma.
IMPRESSION: Lipoma.
Mixed-Density Circumscribed Masses
Fibroadenolipoma
A hamartoma or fibroadenolipoma is a benign tumor composed of normal mammary tissue (adipose, fibrous, and glandular), including ducts and lobules of varying amounts. The lesion is relatively uncommon, with a frequency of 16 in 10,000 mammograms in a series by Hessler et al. (18). In this series, the patients ranged in age from 27 to 88 years and presented with a breast mass of a consistency similar to that of the adjacent tissue (18).
On mammography (Figs. 4.14,4.15,4.16,4.17,4.18,4.19,4.20,4.21,4.22), the appearance of a fibroadenolipoma is usually pathognomonic (18,19,20,21). Depending on the amount of fat versus parenchymal tissue, the lesion may vary from a relatively radiolucent mass to a relatively radiodense mass. The borders are very well defined, and a thin pseudocapsule may be evident. There is a loss of normal architecture of the mammary tissue with lack of orientation of glandular elements toward the nipple. The hamartoma displaces away the normal parenchyma of the breast, which appears to be draped over the lesion. Helvie et al. (22), however, found the mammographic findings of hamartomas to range from the mixed-density circumscribed mass to the isodense,
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more irregular lesions that were biopsied because of the concern of possible malignancy.
Figure 4.2 HISTORY: A 53-year-old woman with a palpable mobile left breast mass. Mammography: Left MLO (A) view shows a large radiolucent round mass extending from the chest wall forward and draping the normal parenchyma over its margin. On spot magnification (B), the thin capsule of the mass is evident.
IMPRESSION: Lipoma, BI-RADS® 2.
Figure 4.3 HISTORY: A 61-year-old woman for screening mammography.
MAMMOGRAPHY: Bilateral MLO (A) and CC (B) views show an asymmetric appearance of the breasts. The left breast appears larger and more fatty than the right breast. On close inspection, there is draping of the glandular tissue on the left around a large radiolucent mass (arrows).
IMPRESSION: Lipoma.
NOTE: Large benign lesions such as lipomas are often evident because of the displacement and draping of the normal parenchyma around their margin.
Figure 4.4 HISTORY: A 37-year-old woman with a palpable mass in the upper aspect of the right breast. She had no history of trauma.
MAMMOGRAPHY: Right MLO (A) and enlarged MLO (B) views. There is a round, circumscribed radiolucent mass in upper aspect of the right breast, marked with a BB. Because of the completely radiolucent characteristics, this mass is a lipoma or a large oil cyst. Without a history of trauma, lipoma is the most likely diagnosis.
IMPRESSION: Lipoma.
On sonography, the lesion is well defined and composed of lobulated sonolucent areas mixed with irregular echogenic planes (23). If large and cosmetically a problem, or if not clearly of mixed density mammographically, the lesion is treated with complete excision and enucleation. No association with malignancy has been described.
Intramammary Nodes
Intramammary lymph nodes have an appearance similar to that of axillary nodes; namely, they are well defined, mixed density or medium to low density, round, ovoid, or reniform nodules with a fatty notch or center (Figs. 4.23,4.24,4.25,4.26,4.27). Intramammary nodes can be found throughout the breast (24) but most commonly are located in the middle- to upper-outer aspect of the breasts and are
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often multiple and bilateral. Intramammary nodes are located in the superficial soft tissue in the vast majority of cases.
Figure 4.5 HISTORY: A 79-year-old gravida 3, para 3 woman with a history of the right breast being larger than the left for years (A).
MAMMOGRAPHY: Bilateral mediolateral views (B). There is marked asymmetry in the size of the breasts. There is a large radiolucent mass surrounded by a thin capsule (straight arrow) in the right upper-outer quadrant. The mass compresses and drapes the normal parenchyma around it. These findings are characteristic of a lipoma. The ovoid nodules present in the superior aspect of the breast (curved arrow) are lymph nodes superimposed over the large lipoma.
IMPRESSION: Lipoma.
Most intramammary nodes are less than 1 cm in diameter. Nodes may increase in diameter and be benign, although if the mass does not have a fatty hilum, biopsy may be necessary to confirm its etiology. In a study of 158 whole-breast specimens with primary operable carcinoma, Egan and McSweeney (25) found intramammary lymph nodes in 28% and metastatic deposits in intramammary nodes in 10%. Although nodes involved with metastatic disease may enlarge and become more rounded and dense (24), this is not necessarily the case, and nodes of less than 1 cm in diameter can be malignant (25).
On ultrasound, lymph nodes also have a characteristic appearance. They are very well defined and oval or lobular with mixed echogenicity. The cortex is hypoechoic, and the fatty hilum is hyperechoic. Abnormal nodes may lose this appearance and be more rounded and poorly marginated.
Other benign conditions also may be associated with the presence of intramammary nodes as well as axillary adenopathy. These include rheumatoid arthritis (26), sarcoidosis (27), psoriatic arthritis, and systemic lupus erythematosus (24). Enlarged dense nodes may be present in these conditions as well as in lymphoma. Often, in the case of adenopathy, the fatty hilum is lost and the node is isodense or even of high density.
Skin Lesions
It is critical that the technologist indicate any skin lesions on the patient’s breasts. Moles, keratoses (Figs. 4.28,4.29,4.30), retracted nipples (Figs. 4.31 and 4.32), scars
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(Fig. 4.33), and neurofibromas (Fig. 4.34) may appear as very-well-defined masses of mixed or medium density on at least one of the projections. As the lesion is compressed against the breast, air is trapped around it, creating an especially lucent halo. If the surface is irregular, a crenulated appearance is noted, creating a mixed density on mammography. By turning the breast with the lesion in tangent, the well-defined mass disappears or projects at the skin surface. Artifacts on the patient’s skin, including electrocardiogram pads and various patches for transdermal medications, may trap air underneath, producing a “mixed-density mass” appearance on mammography (Fig. 4.35).
Figure 4.6 HISTORY: A 51-year-old woman with fullness in the left breast superiorly.
MAMMOGRAPHY: Left MLO (A) and CC (B) views show a fatty replaced breast. There is a large radiolucent mass with circumscribed margins (arrows) projecting forward from the chest wall. The mass is associated with eggshell and lucent centered calcifications of fat necrosis.
IMPRESSION: Lipoma with fat necrosis.
NOTE: Lipomas may be associated with small areas of fat necrosis and dystrophic or eggshell calcifications. The observation of a lipoma in a fatty breast is difficult, and the primary finding is the thin capsule.
Isodense to High-Density Masses
There is considerable overlap between the lesions that are of medium density or isodense with the background parenchyma and the lesions that are of high density (2). Cysts and fibroadenomas tend to be of isodense, and the background stromal markings may be visualized through the masses. Carcinomas tend to be of higher density, but these divisions are not absolute, and several benign lesions—including fibroadenomas, hematomas, and abscesses—may be of high density, depending on their
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size. Margination of the mass is important in suggesting a malignant etiology. Also, a multimodality approach to these masses, including physical examination, mammography, and ultrasound, is important in determining the approach for further evaluation (28).
Figure 4.7 HISTORY: Patient recalled for magnification view of the right breast.
MAMMOGRAPHY: Right CC magnification view demonstrates a round, thin-walled lucent mass in the superficial area. Within this mass are a few faint punctuate microcalcifications. The findings are typical of fat necrosis, with formation of an oil cyst and early calcification in its wall.
IMPRESSION: Oil cyst.
Figure 4.8 HISTORY: A 74-year-old woman for screening mammography.
MAMMOGRAPHY: Left CC (A) view shows a round, circumscribed, fat-containing mass located medially (arrow). On the enlarged image (B), the very-well-demarcated margin of the radiolucent mass is seen. The findings are typical of an oil cyst.
IMPRESSION: Oil cyst.
Figure 4.9 HISTORY: A 63-year-old woman who has a small palpable mass in the right breast at 12 o’clock. She had a car accident with bruising of the right breast 1 year ago.
MAMMOGRAPHY: Right CC (A) view shows a small round mass (arrow) in the subareolar region, corresponding to the palpable lesion. On the enlarged image (B), the circumscribed mass of very low density is seen. The nearly radiolucent lesion implies a fat containing mass. Ultrasound (C) shows a complex cystic mass. A fluid level is seen in the cyst, and it is located in the subcutaneous area, all of which are features of fat necrosis.
IMPRESSION: Fat necrosis, oil cyst.
Figure 4.10 HISTORY: A 50-year-old woman with a palpable mass in the inferior aspect of the right breast.
MAMMOGRAPHY: Bilateral MLO (A) views show heterogeneously dense breasts. There is a small round mass marked by a BB in the right breast at 6 o’clock in the area of palpable concern. On spot-magnification ML (B) and CC (C) views, the area contains multiple round circumscribed fat containing masses with thin rims.
IMPRESSION: Oil cysts, BI-RADS® 2.
Figure 4.11 HISTORY: A 41-year-old woman with multiple small palpable masses bilaterally. There is no history of trauma.
MAMMOGRAPHY: Bilateral MLO (A) views show multiple round masses marked by BBs in the breasts and axillae. On enlarged images (B, C, D), the masses are very well circumscribed and radiolucent, consistent with oil cysts. Because of the extensive nature of these, the findings are consistent with steatocystoma multiplex.
IMPRESSION: Steatocystoma multiplex.
Figure 4.12 HISTORY: A 32-year-old gravida 1, para 1 patient who stopped nursing 4 months earlier, presenting with a small right subareolar nodule.
MAMMOGRAPHY: Right CC (A) and enlarged (2÷) CC (B) views. The breast is quite dense, consistent with the patient’s age and her recent lactating state. In the subareolar area, corresponding to the palpable nodule, there is a small circumscribed radiolucent nodule (arrows). The differential for this nodule includes a lipoma, an oil cyst, or a galactocele, and given the clinical history, a galactocele is most likely. The lesion appears radiolucent because of the fat content of the milk it contains.
IMPRESSION: Galactocele.
NOTE: The patient was followed clinically, and the nodule resolved.
Figure 4.13 HISTORY: A 38-year-old woman who is lactating and presents with a palpable mass in the left breast.
MAMMOGRAPHY: Left MLO (A), CC (B), and enlarged ML (C) views and ultrasound (D). There is a round circumscribed mixed-density mass in the left upper-outer quadrant (A, B) marked with a BB. In addition, there is a second smaller isodense mass located medially. In the center of the breast is a small radiolucent mass (arrow) that has a circumscribed margin. Ultrasound of the palpable mass shows it to be echogenic and to contain a small cystic area. Based on the history of the patient and the findings, the masses are most consistent with galactoceles. The patient underwent drainage of the two larger lesions, revealing milk contents.
IMPRESSION: Galactoceles.
Figure 4.14 HISTORY: A 45-year-old woman with a palpable left breast mass.
MAMMOGRAPHY: Left spot compression MLO view shows a very-well-circumscribed mass of mixed density. This mass is composed of fat as well as fibrous and glandular tissues and is surrounded by a thin capsule (arrows).
IMPRESSION: Fibroadenolipoma (hamartoma).
The sonographic features of a benign solid mass are a thin pseudocapsule (29), an ellipsoid shape, fewer than four gentle lobulations, and extensive hyperechogenicity (30). Based on these criteria, Stavros et al. (30) found the negative predictive value to be 99%. Although sonography cannot definitely differentiate benign from malignant solid masses, the correlation of a circumscribed mass that has not enlarged on mammography and benign sonographic characteristics can be used to follow rather than biopsy a nonpalpable lesion.
Malignant sonographic criteria (30) include spiculation, a taller-than-wide shape, angular margins, shadowing, branching pattern, hypoechoicity, duct extension, and microlobulation. The presence of these features, even in the face of a relatively circumscribed mass on mammography, should prompt biopsy.
Cysts
One of the manifestations of fibrocystic disease is simple cysts that may vary from 3 mm to several centimeters in diameter. Cysts are more commonly seen in women 30 to 50 years old. Pain and tenderness may accompany the development of a cyst, and the symptoms may occur just before and with the menstrual cycle. There appears to be a relationship between caffeine consumption and fibrocystic disease. Boyle et al. (31) found that women who consumed 31 to 250 mg of caffeine per day had a 1.5-fold increase and those who consumed more than 500 mg/day had a 2.3-fold increase in the odds of fibrocystic disease. Allen and Froberg (32), however, found in a study of patients with suspected benign proliferative breast disease that a decrease in caffeine consumption did not result in a significant reduction of palpable breast nodules or in lessening of breast pain.
Cysts are derived from the lobules and may be lined by ordinary mammary epithelium or by an apocrine-type epithelium (33). A tension cyst is an apocrine cyst that contains fluid under pressure, secondary to obstruction of the outflow tract (33). Clinically, cysts are tender, circumscribed masses that are mobile, ranging from soft to firm, depending on the degree of distension.
On mammography, cysts (Figs. 4.36,4.37,4.38,4.39,4.40,4.41,4.42,4.43) are very well-defined, round or ovoid masses that may vary from several millimeters to 5 cm or more in diameter (34). The density is usually equal to or slightly greater than that of parenchyma. A halo sign is often present, and the orientation of the cyst is along the path of the ducts. Cysts may be multilocular or multiple and may be associated with other findings of fibrocystic disease. It is important when multiple masses are present that each lesion be evaluated individually so that a well-defined carcinoma not be missed.
On sonography, cysts are well defined and anechoic, with well-defined walls and good through-transmission of sound. If echoes are present within a lesion thought to be a cyst, aspiration should be performed for complete evaluation. Pneumocystography also may be performed at the time of aspiration to outline the internal aspect of the cyst wall. When sonography demonstrates a complicated cyst (imperceptible wall, acoustic enhancement, and low-level echoes) or a cluster of microcysts, the likelihood of malignancy is very low.
Cystic masses with thick walls, thick septae, or an intracystic solid component or predominately solid masses with cystic foci are categorized as complex cysts. Complex cysts may be malignant, and biopsy is warranted. In a study of cystic lesions, Berg et al. (35) found that none of the 38 complicated cysts or the 16 clustered microcysts were malignant; however, 18 of the 79 complex masses were malignant. Papillomas and intracystic papillary carcinomas may develop within a cyst and usually cannot be
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differentiated radiographically (36). Invasive papillary carcinomas tend to present as multiple, relatively well-defined masses. If a cyst contains an intracystic lesion, lobulation or slight irregularity of the wall may be seen on mammography. On pneumocystography, papillary lesions are seen as a polypoid filling defect within the cyst cavity.
Figure 4.15 HISTORY: A 30-year-old woman with a palpable mass in the right subareolar area.
MAMMOGRAPHY: Right MLO (A) and CC (B) views show a lobular circumscribed mass in the subareolar area. On spot compression (C, D), the mass is of mixed density and is surrounded by a thin capsule. On ultrasound (E), the mass is very well defined and elliptical in shape. The echo pattern is mixed, with echogenic bands traversing a primarily hypoechoic mass. The mammographic and sonographic findings are typical of a hamartoma.
IMPRESSION: Hamartoma (fibroadenolipoma), BI-RADS® 2.
Figure 4.16 HISTORY: A 62-year-old woman with a palpable mass in the right breast at 6 o’clock.
MAMMOGRAPHY: Bilateral CC (A) and MLO (B) views show a circumscribed, round mixed-density mass in the left breast at 12 o’clock (arrows). On the right, there is a BB marking the palpable mass posteriorly. The palpable mass is radiolucent and has a thin pseudocapsule (arrowhead). Enlarged image (C) of the left breast mass shows its thin capsule (arrow) and heterogeneous composition, consistent with a hamartoma. Enlarged ML image (D) of the right breast mass shows it to be completely radiolucent, which is consistent with a lipoma.
IMPRESSION: Left breast hamartoma, right breast lipoma.
Fibroadenoma
A fibroadenoma is a benign tumor of the breast, usually presenting with a well-defined mass. The term fibroadenoma was first used by Bilroth in 1880 (37). Being estrogen-sensitive tumors, fibroadenomas usually appear in adolescents and young women before the age of 30 years. Their growth may be enhanced by pregnancy or lactation (38). After menopause, these tumors undergo mucoid degeneration, hyalinize, and eventually develop characteristic coarse calcifications.
Dupont et al. (39), in a study of 1,835 patients with fibroadenomas, found that there was a slight increase in the risk of breast cancer in women diagnosed with fibroadenoma. However, the histologic features of the fibroadenoma influenced the risk of breast cancer. Fibroadenomas with associated proliferative disease in the epithelium or in those patients with positive family history of breast cancer were considered to be at increased long-term risk.
In a study of the follow-up of fibroadenomas, Carty et al. (40) found that at 5 years after diagnosis, 52% of the fibroadenomas had reduced in size, 16% were unchanged, and 32% had grown. When fibroadenomas have been diagnosed based on a triple test of mammography, clinical examination, and cytology, or have been diagnosed on percutaneous tissue sampling with a core needle, usual management is follow-up rather than excision. If an incidental nonpalpable fibroadenoma is identified at mammography and confirmed as having benign sonographic features (30), early imaging follow-up rather than biopsy is typically performed.
On histology, fibroadenomas are composed of dense, connective-tissue stroma surrounding canaliculi or tubules lined with ductal epithelium (41). On clinical examination, these tumors are smooth and of firm or rubber consistency and freely movable. In young patients, fibroadenomas may reach a very large size. This variant, sometimes termed the juvenile fibroadenoma, is characterized by rapid growth rate in young women and an increase in stromal cellularity (42).
The mammographic findings (Figs. 4.44,4.45,4.46,4.47,4.48,4.49,4.50,4.51) of a fibroadenoma are an isodense, very-well-defined, round, ovoid, or smoothly lobulated mass (43). A fatty halo surrounds the lesion and may be the key to identifying a
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fibroadenoma in a young dense breast. Calcifications may vary from punctuate peripheral deposits to the typical coarse popcornlike morphologies that are characteristic of fibroadenomas. On ultrasound, fibroadenomas are usually smooth, hypoechoic masses of homogeneous echo-texture with well-defined margins and no attenuation or enhancement of sound posteriorly (44) (Figs. 4.52 and 4.53).
Figure 4.17 HISTORY: A 49-year-old woman with a palpable left breast mass.
MAMMOGRAPHY: Bilateral MLO (A) and CC (B) views show masses in both upper-outer quadrants. On the right, a large circumscribed mixed-density mass (arrow) is present, consistent with a hamartoma. On the left, the palpable mass is high density and irregular with indistinct margins. An enlarged lymph node is also seen in the left axilla.
IMPRESSION: Hamartoma, right breast, carcinoma left breast, metastatic to the axillary nodes.
HISTOPATHOLOGY: Left breast: Invasive ductal carcinoma with metastatic nodes in the left axilla.
Figure 4.18 HISTORY: A 57-year-old woman for screening mammography.
MAMMOGRAPHY: Bilateral MLO (A) and CC (B) views show an oval circumscribed mass in the right upper-outer quadrant. Fat is interspersed with the dense components of the mass, indicating a benign nature.
IMPRESSION: Hamartoma (fibroadenolipoma).
Figure 4.19 HISTORY: A 53-year-old gravida 8, para 4, abortus 4 woman with a 4-cm palpable soft mass in the left middle-inner quadrant.
MAMMOGRAPHY: Left CC (A) and enlarged (2.5÷) CC (B) views. The breast is dense for the age and parity of the patient. A BB was placed over the palpable lesion. Beneath the BB, there is striking area of asymmetry (arrow) that is fatty in contrast to the background of dense parenchyma; within this fatty mass are two lobulated isodense nodules. Portions of a capsule are seen (arrowhead) surrounding this heterogeneous mass. The appearance is characteristic of a fibroadenolipoma of the breast.
IMPRESSION: Fibroadenolipoma (hamartoma).
Figure 4.20 HISTORY: A 52-year-old gravida 0 woman for screening.
MAMMOGRAPHY: Left MLO (A) and CC (B) views. Scattered fibroglandular tissue is present. In the upper-outer quadrant, there is a large, mixed-density circumscribed mass. A thin pseudocapsule (arrows) surrounds the lesion that is primarily fatty but contains some glandular elements. The lesion is very smoothly marginated and drapes the background parenchyma over it. The appearance of this lesion is characteristic of a benign hamartoma or fibroadenolipoma.
IMPRESSION: Hamartoma.
Rarely, a fibroadenoma may contain or be associated with malignancy (45,46), usually an in situ carcinoma. Fibroadenomas containing malignancy may be indistinguishable from benign fibroadenomas, but features that Baker et al. (47) found of concern were the large size of the mass, indistinct margins, and clustered microcalcifications. Even so, a palpable solid mass having an appearance consistent with a fibroadenoma or a nonpalpable enlarging mass are often biopsied because a well-circumscribed malignancy can have a similar appearance.
Large fibroadenomas has been described (48,49,50) to develop in transplant patients who are on cyclosporin A therapy. Weinstein et al. (48), in a study of five patients with cyclosporin-induced fibroadenomas, found that the masses ranged from 4 cm to 16 cm in diameter. In another study of renal transplant patients aged 27 to 50 years, Baildam et al. (49) found that 13 of 29 patients on cyclosporin developed fibroadenomas, in comparison with 0 of 10 patients not on cyclosporin.
Phylloides Tumor
Phylloides tumor is a fibroepithelial breast tumor that has malignant potential. Previously called cystosarcoma
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phylloides, the name refers to the leaflike pattern of growth of the epithelial elements, not to prognosis. Most phylloides tumors are benign or have limited invasion into the surrounding parenchyma. If the tumors are not completely excised, they may recur (51). When the lesions are malignant, metastases most often occur to lung, pleura, and bone (52).
Figure 4.21 HISTORY: Baseline screening mammogram on a 40-year-old woman. There were no abnormalities noted on physical examination of the breasts.
MAMMOGRAPHY: Right MLO (A) and enlarged MLO (B) views show a large oval circumscribed mass in the upper aspect of the breast. Key to the diagnosis in this case is the density of the mass and the physical examination. The mass is of mixed density with small pockets of fat interspersed within the dense tissue. The lack of a palpable finding to correspond to such a large mammographic mass suggests a benign etiology.
IMPRESSION: Fat-containing mass consistent with a hamartoma (fibroadenolipoma).
NOTE: The mass was stable on subsequent routine mammography.
Phylloides tumors are rare, presenting at a mean age of 40.5 years (53). On palpation, a firm, mobile, smooth mass is found; the lesion may be rapidly enlarging. Mammographically, the tumor is well circumscribed, large, and dense, having an appearance similar to that of a large fibroadenoma (54,55) (Figs. 4.54,4.55,4.56). Coarse calcification within a large circumscribed tumor should suggest, more likely, a fibroadenoma. When calcification occurs in a phylloides tumor, it has been described as plaquelike (11). Histologically, a phylloides tumor has a more cellular, pleomorphic connective tissue component than a fibroadenoma. Epithelially lined clefts are present within the lesion. The microscopic features of the connective-tissue component determine if the lesion is considered benign or malignant (56).
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Figure 4.22 HISTORY: Screening mammogram on a premenopausal patient.
MAMMOGRAPHY: Right MLO (A), CC (B), and enlarged CC (C) views show a mixed-density mass in the lower-inner quadrant (arrow). The lesion contains fat as well as multiple isodense lobulated masses, and it is surrounded by a fatty halo. The findings are characteristic of a fibroadenolipoma or hamartoma.
IMPRESSION: Hamartoma.
Other Benign Masses
Other benign lesions that may present mammographically as well-defined isodense masses include focal fibrocystic lesions, papillomas, hematomas, abscesses, pseudoangiomatous stromal hyperplasia, vascular tumors, sclerosing lobular hyperplasia, tubular adenomas, lactating adenomas, and epidermal inclusion or sebaceous cysts.
Occasionally, focal fibrosis, sclerosing adenosis, or areas of ductal hyperplasia can present as well-circumscribed masses (Figs 4.57,4.58,4.59,4.60,4.61). The mammographic appearance is nonspecific, and many of these lesions are associated with microcalcifications. Focal fibrosis is characterized by abundant connective tissue with intervening ducts and lobules that are atrophic (57). Focal fibrosis is common in young women with a palpable lump and is frequently diagnosed on core needle biopsy of solid circumscribed lesions. The most common presentations of focal fibrosis are a mass that is relatively circumscribed and solid or a developing density (58). Biopsy is usually necessary to exclude a malignant process. Nodular adenosis or “adenosis tumor” is a confluent area of sclerosing adenosis that forms a mass. The mammographic appearance is usually a circumscribed ellipsoid or hypodense mass (59,60).
Intraductal papillomas are benign intraductal lesions characterized by a frondlike epithelium on a fibrovascular core. Most authors (61,62) do not consider papillomas to be precursors to papillary carcinoma or to elevate the risk of developing breast cancer, although some do suggest that papillomas increase the risk of cancer somewhat (63).
Solitary intraductal papillomas are often not evident on the mammogram and instead are detected on galactography. When small, these lesions present typically with a nipple discharge, usually sanguineous or serosanguineous (64). If papillomas are identified on mammography (Fig. 4.62), they generally are small, well-defined
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lesions oriented along the path of the ducts and often located in the subareolar area. A tubular shape should suggest the possibility of a papilloma. Because papillomas have a delicate blood supply via their stalk, they have a tendency to infarct (64). Calcification that is nonspecific may occur in infarcted papillomas.
Figure 4.23 HISTORY: A 42-year-old woman referred for evaluation of a mass noted on mammography.
MAMMOGRAPHY: Left MLO view shows a focal density centrally and a lobulated circumscribed mass (A, arrow) superiorly. On the enlarged image (B), the mass is noted to be reniform and to have a fatty hilum. On ultrasound (C), the mass is circumscribed and of mixed echogenicity. The typical findings of a normal lymph node are seen: elongated shape, hypoechoic cortex, and hyperechoic fatty hilum.
IMPRESSION: Intramammary node.
Figure 4.24 HISTORY: A 42-year-old woman with a small palpable lump in the right axilla.
MAMMOGRAPHY: Right MLO (A) view shows a BB marking the palpable abnormality. On the axillary view (B), the typical appearance of a normal lymph node (arrow) is seen: a reniform shape, well circumscribed margins, and a fatty hilum.
IMPRESSION: Normal axillary lymph node.
Figure 4.25 HISTORY: A 54-year-old woman for screening.
MAMMOGRAPHY: Left CC magnification (1.5÷) view. There is a circumscribed nodule located superficially in the outer aspect of the breast. The fatty hilum (arrow) is characteristic of an intramammary lymph node.
IMPRESSION: Intramammary lymph node.
Figure 4.26 HISTORY: A 54-year-old woman for screening.
MAMMOGRAPHY: An enlarged CC image of the lateral aspect of the right breast shows a circumscribed round mass located superficially. The lesion has a radiolucent center, consistent with the hilum of a normal intramammary lymph node.
IMPRESSION: Intramammary node.
A hematoma may be lobulated and appear as a circumscribed mass or be interstitial and dissect through the tissues, creating a diffuse increased density (Figs. 4.63,4.64,4.65). The density of a hematoma is the same or slightly greater than that of the parenchyma. The margins of the lesion are often slightly indistinct, but particularly in the case of a postoperative hematoma or seroma, the initial finding is that of a well-circumscribed mass. As a hematoma contracts, it may appear more indistinct in margination. Overlying skin edema is usually present in the acute stage with the bruising noted on the clinical examination. Follow-up examinations will show gradual resolution of the fluid collection.
Pseudoangiomatous stromal hyperplasia (PASH) is a benign stromal proliferation with a probable hormonal etiology. The lesion is composed of a complex pattern of anastomosing channels lined by spindle-shaped stromal cells that simulate endothelium. The lesion can be mistaken for a vascular lesion on histology because of this pattern. Polger et al. (65) described the imaging findings associated with PASH. The authors described seven patients with this entity and found that 5 of 7 cases were either circumscribed or partially circumscribed noncalcified masses on mammography.
Lactating adenoma is a benign mass that occurs in response to the physiologic changes that affect the breast during pregnancy and lactation (66). The lactating adenoma usually has a mammographic and sonographic appearance similar to a fibroadenoma, namely a well-circumscribed, hypoechoic mass (67). However, in some
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cases, the margins of the adenoma are more indistinct. Because of the similarity to the appearance of a circumscribed cancer, biopsy is usually necessary (67).
Figure 4.27 HISTORY: Baseline screening mammogram.
MAMMOGRAPHY: Left MLO (A), and CC (B) views show essentially fatty replaced tissue. There is an oval circumscribed mass in the superficial aspect of the axillary tail. On spot compression (C), the fatty hilum is seen, confirming that this is a node.
IMPRESSION: Normal intramammary node.
Figure 4.28 HISTORY: Screening mammogram.
MAMMOGRAPHY: Right CC (A) view and enlarged CC view (B) show a BB marking a pedunculated skin lesion. The crenulated surface is easily visible because of air trapped within the crevices of the keratosis.
IMPRESSION: Keratosis.
Figure 4.29 HISTORY: A 38-year-old woman for screening.
MAMMOGRAPHY: Left MLO view shows heterogeneously dense tissue. A BB marks a very-well-demarcated mass (arrow) in the axillary tail. This represented a large pedunculated skin lesion on clinical examination.
IMPRESSION: Skin lesion.
Sclerosing lobular hyperplasia is a benign lesion that most commonly occurs in young black women (68). The lesion typically presents as a palpable mobile mass. Sclerosing lobular hyperplasia is similar to a fibroadenoma both in its presentation and in its mammographic appearance.
Tubular adenomas are rare benign tumors that occur in women younger than 35 years. Histologically, these masses are related to fibroadenomas. However, instead of containing large ducts, as are found in fibroadenomas, the tubular adenomas are composed of acinar or lobular units as the epithelial component. In young women, tubular adenomas look like noncalcified fibroadenomas, but in older women, they may resemble malignant masses with microcalcifications (69).
Epidermal inclusion cysts or sebaceous cysts are of skin origin; therefore, they are superficially located. Sebaceous cysts are palpated as smooth, firm cutaneous nodules. These very-well-defined lesions are often located in the areolar area or in the lower aspect of the breast and are contiguous with the skin on mammography (4) (Figs. 4.66,4.67,4.68). Epidermal inclusion cysts usually appear as a circumscribed mass that is noncalcified, although occasionally heterogeneous microcalcifications may be noted on mammography within the mass (70). On ultrasound, the inclusion cyst is hypoechoic depending on the amount of debris, with good through-transmission of sound. Extension of the mass into the dermis is often seen as well (70).
Moles and skin lesions, if smoothly marginated, appear as isodense superficial masses on mammography. A normal structure that may stimulate a well-defined mass is the nipple out of profile. With care taken to keep the nipple in profile on both views or at least on one view, there should not be any doubt as to whether a well-defined lesion represents the nipple. If there is a question, a radiopaque marker may be placed on the nipple and the film repeated with the nipple in profile.
An acute breast abscess is usually suspected in clinical examination because of the associated findings of inflammation: a painful tender breast, redness of the skin, and fever. Abscesses most often occur in the postpartum patient, but they also may occur in older patients as well. Because of the inflammation associated with an acute abscess, skin thickening and a surrounding edema pattern are present and may obscure the abscess itself. Mammography with good compression is difficult to perform because of the severe breast tenderness present. When the abscess is visualized, it is usually a relatively well-defined mass (11) (Figs. 4.69 and 4.70). After an abscess has resolved completely, repeat mammography should be performed to exclude an underlying malignancy, particularly in a nonlactating patient.
Vascular tumors of the breast are rare. Most often vascular masses that are located in the subcutaneous area, superficial to the anterior pectoralis fascia, are benign (71). Hemangiomas are superficial, circumscribed masses that are round or lobular (72,73). On ultrasound, hemangiomas may be hypoechoic or intensely hyperechoic (71). Hemangiopericytoma may also rarely occur in the breast (74) and present as a circumscribed soft tissue mass.
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Figure 4.30 HISTORY: A 77-year-old gravida 3, para 3 woman for screening mammography.
MAMMOGRAPHY: Left CC (A) and enlarged (2÷) (B) views. The breast is heterogeneously dense. There is a mixed-density lesion (arrows) in the outer aspect of the breast. The crackled appearance is typical of air in the surface of a skin lesion.
IMPRESSION: Skin lesion (seborrhea keratosis) simulating a breast mass.
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Figure 4.31 HISTORY: A 69-year-old woman for screening.
MAMMOGRAPHY: Right anterior MLO (A) view shows a small calcified mass superiorly (arrow). There is also a more indistinct lobular mass inferiorly (arrowhead). Repeat MLO (B) view, which is better positioned, shows that the inferior “mass” represents the nipple out of profile. The subareolar calcified mass and a larger calcified fibroadenoma posteriorly are seen.
IMPRESSION: Nipple out of profile, calcified fibroadenomas.
Figure 4.32 HISTORY: A 56-year-old woman for follow-up of a nonpalpable right breast nodule that had been stable for 5 years.
MAMMOGRAPHY: Right MLO (A) and CC (B) views. In the central aspect of the breast, there is a well-circumscribed ovoid nodule (straight arrow) that was stable from prior examinations and presumed to be a fibroadenoma (A and B). A second nodule (curved arrow), seen superiorly on the MLO view (A), disappears on the CC view (B). This represents the nipple out of profile, simulating a breast lesion.
IMPRESSION: Nipple out of profile, stimulating a breast lesion.
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Figure 4.33 HISTORY: A 70-year-old woman with a history of benign breast biopsies, for screening mammography.
MAMMOGRAPHY: Bilateral MLO (A) and CC (B) views show very-well-defined densities bilaterally, marked with wires indicating the biopsy sites. These densities have very defined edges, suggesting that the lesions are on the skin and are demarcated by air haloes. Clinical examination confirmed keloids.
IMPRESSION: Keloids at biopsy sites.
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Figure 4.34 HISTORY: A 57-year-old woman with neurofibromatosis, for screening mammography.
MAMMOGRAPHY: Bilateral MLO (A) and CC (B) views. The breasts are fatty replaced. There are multiple, very-well-defined masses of varying size projected over the skin surfaces of both breasts, compatible with the obvious cutaneous lesions on physical examination. Note on the MLO views (A) that the lesions that superimpose over the breast have strikingly lucent haloes (curved arrows), more lucent than is seen with a fatty halo. This appearance is created by air surrounding the nodule compressed against the surface of the breast.
IMPRESSION: Multiple cutaneous lesions of neurofibromatosis.
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Figure 4.35 HISTORY: A 65-year-old woman with angina, for screening mammography. She had had no recent breast interventional procedures.
MAMMOGRAPHY: Left MLO view. There is a very-well-circumscribed mixed-density mass superimposed over the upper aspect of the left breast. The lucencies within the mass are more radiolucent than fat, suggesting air beneath a device on the skin. An unusual appearance of a pneumocystogram or air within a mass or hematoma from recent biopsy would also be a consideration with an appropriate clinical history.
IMPRESSION: Air trapped beneath a Nitro-Bid patch on the skin, simulating a breast lesion.
NOTE: The patient had placed the new patch on her breast just before the mammogram and refused to have the technologist remove it for the study.
Well-Circumscribed Carcinoma
Primary breast carcinoma characteristically presents mammographically as a spiculated mass. However, some carcinomas are relatively well defined or even very sharply marginated, and these lesions may be confused with benign masses, such as fibroadenomas, radiographically. Radiologists must be aware of the subtle features of breast cancer, which include relatively circumscribed masses, to avoid the pitfall of missing carcinomas presenting in this way (75) (Figs. 4.71,4.72,4.73,4.74,4.75,4.76,4.77,4.78,4.79,4.80,4.81,4.82,4.83,4.84,4.85,4.86).
It has been said (11) that approximately 2% of carcinomas are very-well-defined masses. Moskowitz (76) found 2% of carcinomas to be very well defined and 5% to 10% to be partially well defined. Marsteller and Shaw de Paredes (77) found that 4.1% of relatively circumscribed lesions were carcinomas, and an additional 4% were atypical hyperplastic lesions. If one considers nonpalpable breast cancers only, however, a greater percentage (4%) appear very sharply marginated (78). Most relatively circumscribed carcinomas are ductal carcinomas, which are the most frequently occurring primary carcinomas of the breast. Intraductal or infiltrating ductal carcinomas can be well defined on mammography, although there is usually some indistinctness of the margins of the infiltrating lesions. In a series of 350 cases of intraductal carcinomas, Mitnick et al. (79) found that 13 lesions were sharply circumscribed lesions simulating benign masses. Calcifications within these masses tend to be pleomorphic, amorphous and asymmetric in location within the nodules.
The types of carcinomas that more characteristically appear as well-defined masses are medullary mucinous and papillary cancers, which are subtypes of invasive ductal carcinoma. However, because invasive ductal carcinoma not otherwise specified (NOS) accounts for the vast majority of breast cancers, a frequent histologic type of cancer that presents as a well-circumscribed mass is invasive ductal NOS. It is very uncommon that invasive lobular carcinoma appears as a circumscribed mass (80).
Medullary carcinoma accounts for 3% of all breast cancers (81). Clinically, the lesions are soft and movable, and unlike the irregular scirrhous carcinomas, medullary carcinomas do not necessarily palpate as larger than they appear mammographically. The lesions tend to be located either deep in the breast or in the subareolar or subcutaneous areas (82). Histologically, medullary carcinoma is a variety of ductal carcinoma characterized by a growth pattern of syncytial, solid sheetlike areas of malignant cells. Necrosis is frequent; calcification does not usually occur (83). The mammographic appearance is of a well-circumscribed, medium- to high-density noncalcified mass. Faint indistinctness of the borders may be detected, indicating a suspicious nature. On ultrasound,
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medullary carcinomas are well-defined, inhomogeneous hypoechoic masses that show enhanced through-transmission (84).
Figure 4.36 HISTORY: A 64-year-old woman with an abnormal screening mammogram.
MAMMOGRAPHY: Left CC spot compression (A) view shows a circumscribed lobulated mass medially. Ultrasound (B) demonstrates that the lesion is anechoic, smoothly marginated, with a thin wall and acoustic enhancement.
IMPRESSION: Simple cyst.
Mucinous or colloid carcinomas also may present as well-circumscribed masses (82) (Fig. 4.87). However, in a study of 10 patients with pure mucinous carcinoma, Cardenosa et al. (85) found that the majority of masses were poorly defined and lobulated. The density of these lesions tends to be medium to low because of the presence of mucin (82). Mucinous carcinomas, like medullary cancers, tend to be peripherally located.
Pure mucinous carcinoma is a well-differentiated subtype of invasive ductal carcinoma that has a better survival rate than other less differentiated carcinomas (86,87). Wilson et al. (88) found that the mammographic findings in pure mucinous carcinomas were masses with circumscribed, lobular contours that were the result of the expansile growth pattern. Patients with mixed mucinous tumors had masses with more irregular margins than those with pure mucinous carcinoma.
Metastases
Metastases from extramammary primary carcinomas are unusual, accounting for about 1% to 2% (89) of all breast malignancies. The mammographic presentation of a metastasis
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may be as a very well-defined mass having an appearance similar to that of fibroadenoma. Although it is more common for a patient presenting with a metastatic lesion in the breast to have a known carcinoma, it is not necessarily the case (89). The most common sites of origin of metastases to the breast are lymphoma, melanoma, sarcoma, lung, stomach, prostate, and ovary (90) (Figs. 4.88,4.89,4.90,4.91,4.92). In most series (90,91,92), a solitary well-defined mass is the most common presentation, with multiple masses and diffuse involvement of the breast being less likely; others have described diffuse involvement more frequently (92). The lesions tend to be superficially located (90) and may have an appearance similar to that of sebaceous cyst (Figs. 4.77 and 4.78).
Figure 4.37 HISTORY: A 41-year-old gravida 3, para 4 woman with a right subareolar mass.
MAMMOGRAPHY: Bilateral MLO (A) and CC (B) views and ultrasound (C). The breasts are dense and glandular for the age and parity of the patient. In the right subareolar area, there is an isodense, relatively circumscribed mass (arrows) (A and B). A halo is present around the anterior aspect of the lesion, but its posterior margin is indistinct. Ultrasound (C) demonstrates the anechoic nature of the lesion.
IMPRESSION: Simple cyst.
Figure 4.38 HISTORY: A 38-year-old woman with a solitary palpable left breast mass.
MAMMOGRAPHY: Left MLO (A) and CC (B) spot views show the BB marking a palpable mass. The edges are very well defined and the mass is isodense. On ultrasound (C), the mass is well defined and anechoic, consistent with a simple cyst.
IMPRESSION: Simple cyst.
Figure 4.39 HISTORY: A 73-year-old woman with a history of fibrocystic disease, for routine mammography.
MAMMOGRAPHY: Right MLO (A) and CC (B) views show the breast to be heterogeneously dense. There are several partially obscured, round, isodense masses (arrows). The multiplicity of the findings and the appearance suggests that these are most likely cysts. Sonography (C, D) confirms that the masses are simple cysts. They are oval, well defined, and anechoic.
IMPRESSION: Simple cysts bilaterally, BI-RADS® 2.
Figure 4.40 HISTORY: A 62-year-old woman with a palpable mass in the right breast.
MAMMOGRAPHY: Right CC (A) view shows very dense tissue. In the lateral aspect of the breast is a large, round isodense mass that has a fatty halo surrounding its border (arrows). On ultrasound (B), an anechoic oval lesion is seen.
IMPRESSION: Simple cyst.
Figure 4.41 HISTORY: A 42-year-old woman who presents with a new palpable mass in the right breast.
MAMMOGRAPHY: Right MLO (A) view shows a BB overlying the palpable mass in a heterogeneously dense breast. The mass is large, somewhat high density, round, and circumscribed. Just posterior to it is another lower-density round mass (arrow). Ultrasound (B) demonstrates the palpable lesion to be a simple cyst: anechoic and well defined with increased through-transmission of sound. The more posterior mass was also identified as a smaller cyst on ultrasound.
IMPRESSION: Simple cyst.
Figure 4.42 HISTORY: A 51-year-old gravida 1, para 2 woman with a history of fibrocystic disease and lumpy breasts on physical examination.
MAMMOGRAPHY: Bilateral CC views. The breasts are dense and glandular for the age and parity of the patient. There are bilateral, well-defined round masses surrounded by fatty haloes (arrow) and oriented in the direction of the ducts. The multiplicity of findings and the similarity in appearance of the lesions suggest fibrocystic changes. Ultrasound confirmed the cystic nature of the masses.
IMPRESSION: Bilateral cysts, diffuse fibrocystic changes.
Figure 4.43 HISTORY: A 42-year-old gravida 3, para 3 woman with a lump in the right breast.
MAMMOGRAPHY: Right CC view (A) and pneumocystogram (B). The breast is dense and diffusely nodular. There is a moderately high-density, very-well-defined round mass surrounded by a fatty halo. Sonography revealed a cyst. The pneumocystogram (B) shows a normal, thin-walled cavity.
IMPRESSION: Cyst.
Figure 4.44 HISTORY: A 64-year-old woman for screening mammography.
MAMMOGRAPHY: Right MLO (A) view shows a small oval mass located posteriorly (arrow). On spot compression (B), the mass is circumscribed and slightly lobulated. On ultrasound (C), the mass is lobulated, hypoechoic, and slightly taller than wide. Sonographic findings are suspicious and necessitate biopsy.
IMPRESSION: Solid mass, BI-RADS® 4. Biopsy recommended,
HISTOPATHOLOGY: Fibroadenoma.
Lymphoma may occur as a primary or secondary lesion in the breast. Lymphomas may produce axillary or intramammary adenopathy or may present with circumscribed or poorly marginated breast nodules (Figs. 4.79 and 4.80). In a study of 29 women with non-Hodgkin lymphoma affecting the breast, Liberman et al. (93) found that solitary masses were the most frequent presentation. Although mammography showed indistinct or partially circumscribed masses in the majority of cases, well-circumscribed masses were the presentation in 28% of the patients. The development of numerous new round masses bilaterally in a patient who is not on hormone replacement therapy should suggest the possibility of lymphoma.
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Figure 4.45 HISTORY: A 30-year-old gravida 2, para 2 patient with a right breast mass.
MAMMOGRAPHY: Right CC view (A) and ultrasound (B). There is an isodense, very-well-circumscribed mass in the right upper-outer quadrant. A halo surrounds the lesion. On sonography (B), the mass is circumscribed, solid, and of relatively homogeneous hypoechogenicity, suggesting a fibroadenoma.
IMPRESSION: Solid mass, favoring fibroadenoma.
HISTOPATHOLOGY: Fibroadenoma.
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Figure 4.46 HISTORY: A 33-year-old gravida 3, para 0, abortus 3 woman with a palpable mass in the left breast.
MAMMOGRAPHY: Left MLO (A) and enlarged CC (B) views. The breast is dense, compatible with the age of the patient. There is a very-well-circumscribed, lobulated, isodense mass (arrow) in the upper-outer quadrant of the left breast. The lobulated contour suggests that this is most likely a fibroadenoma. Ultrasound confirmed the solid nature of the lesion.
IMPRESSION: Solid mass, probable fibroadenoma.
HISTOPATHOLOGY: Fibroadenoma.
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Figure 4.47 HISTORY: A 57-year-old gravida 7, para 7 woman with a palpable nodule in the right lower-inner quadrant.
MAMMOGRAPHY: Bilateral CC views (A), right MLO view (B), and left MLO view (C). There are three relatively well-circumscribed masses present. In the right inner quadrant (A and B), there is a very-well-marginated high-density mass (straight arrow) located in the subcutaneous area and corresponding to the palpable nodule. Ultrasound of the right (D and E) and left (F) breasts. On ultrasound (D), this mass is complex; there is a fluid component with debris layering in the base. This mass, particularly because of its location, is most consistent with an inclusion or sebaceous cyst. In the right upper-outer quadrant (A and B), there is an isodense circumscribed mass (curved arrow), which on ultrasound (E) is a simple cyst. In the left upper-outer quadrant, a third mass is noted (A and C) (arrowhead). This mass is of isodense and has well-circumscribed lobulated margins, suggesting that the lesion may be a fibroadenoma. Sonography (F) reveals the lesion to be hypoechoic and well marginated, consistent with a fibroadenoma.
IMPRESSION: Three circumscribed masses: simple cyst and sebaceous cyst on the right and fibroadenoma on the left.
HISTOPATHOLOGY: Right epidermal cyst, left fibroadenoma.
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Figure 4.48 HISTORY: Baseline mammogram in a patient who presents with a new palpable lump in the right breast.
MAMMOGRAPHY: Right CC view shows a lobulated, circumscribed, somewhat dense mass in the outer quadrant. Sonography showed the mass to be solid. The lesion has very-well-defined margins, suggesting a benign etiology.
IMPRESSION: Circumscribed mass, favor fibroadenoma. Recommend biopsy to confirm.
HISTOPATHOLOGY: Fibroadenoma.
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Figure 4.49 HISTORY: A 35-year-old woman with palpable nodularity in the upper-outer quadrant.
MAMMOGRAPHY: Right MLO (A) and CC (B) views show dense parenchyma. In the 10 o’clock position, there is a circumscribed mass (arrow) present. Spot compression (C) shows the mass to be lobular, isodense, and partially circumscribed; however, some of the borders are obscured. Ultrasound (D) demonstrates a solid lobular lesion that is somewhat vertical in orientation with a multilobulated border.
IMPRESSION: Solid mass, possible fibroadenoma. Recommend biopsy because of borders on mammography and ultrasound.
HISTOPATHOLOGY: Fibroadenoma.
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Figure 4.50 HISTORY: A 69-year-old woman for screening mammography.
MAMMOGRAPHY: Bilateral MLO view (A) shows lobulated masses containing coarse calcifications bilaterally. On spot magnification views (B, C, D), the masses are circumscribed and lobulated. Coarse and dystrophic calcifications are present in all three masses, and the calcifications are located in the periphery of the lesions.
IMPRESSION: Calcified fibroadenomas.
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Figure 4.51 HISTORY: A 49-year-old woman for screening mammography.
MAMMOGRAPHY: Right MLO (A) and CC (B) views show a lobular isodense mass at the 3 o’clock position (arrows). Spot compression (C) shows that the mass is lobular, isodense, and well circumscribed. Sonography was performed and demonstrated a solid lesion. The mass had developed from a prior study, so biopsy was performed.
IMPRESSION: Circumscribed mass, possible fibroadenoma.
HISTOPATHOLOGY: Fibroadenoma.
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Figure 4.52 HISTORY: A 37-year-old gravida 0, para 0 patient with a palpable mass in the left axillary tail.
MAMMOGRAPHY: Left MLO (A) view shows extremely dense breast tissue. A BB marks the palpable mass, which is a circumscribed, isodense lobular lesion. On the spot magnification view (B), the very-well-defined margins are seen. On ultrasound (C), the mass is hypoechoic, well defined, and somewhat oval.
IMPRESSION: Solid palpable mass, likely fibroadenoma. Recommend biopsy.
HISTOPATHOLOGY: Fibroadenoma.
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Figure 4.53 HISTORY: A 29-year-old woman with a new palpable right breast mass.
MAMMOGRAPHY: Right MLO (A), CC (B), and ML (C) views show heterogeneously dense tissue. There is partially obscured, partially circumscribed, isodense lobular mass in the 12 o’clock position corresponding to the palpable lesion. Ultrasound (D) shows the mass to be solid, hypoechoic, elliptical in shape, and well defined. Because it was palpable, biopsy was performed.
IMPRESSION: Solid palpable mass, likely fibroadenoma.
PATHOLOGY: Fibroadenoma with epithelial hyperplasia.
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Figure 4.54 HISTORY: A 47-year-old woman with a positive family history of breast cancer presents with a palpable right breast mass.
MAMMOGRAPHY: Right MLO (A) view shows a high-density round mass in the superior aspect of the breast. Enlarged image (B) shows the circumscribed margins around a portion of the mass, which is otherwise obscured. On ultrasound (C), the lesion is hypoechoic and somewhat inhomogeneous. Because of the large size and its appearance, a phylloides tumor is a likely possibility. Also included in the differential diagnosis are a giant fibroadenoma and a primary breast carcinoma.
IMPRESSION: Phylloides tumor.
HISTOPATHOLOGY: Phylloides tumor.
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Figure 4.55 HISTORY: A 26-year-old woman with a large, growing palpable mass in the left axillary tail.
MAMMOGRAPHY: Left MLO (A) view shows the breast to be fatty replaced. In the upper-outer quadrant is a high-density, very-large-circumscribed mass. On ultrasound (B), the mass is noted to be solid and well defined. Based on the size of the lesion, a giant fibroadenoma or a phylloides tumor is most likely.
IMPRESSION: Probable phylloides tumor.
HISTOPATHOLOGY: Malignant cystosarcoma phylloides.
Figure 4.56 HISTORY: An 84-year-old woman with a large palpable mass in the right breast.
MAMMOGRAPHY: Right CC view. There is a large mass in the inner quadrant of the right breast with lobulated but well-defined margins. Some dense coarse calcification is present within the lesion. The well-defined contours and the coarse calcification suggest the possibility of a cystosarcoma phylloides, particularly in an elderly patient. Less likely in the differential diagnosis are a fibroadenoma (which probably would have degenerated to a greater degree and calcified) and a well-circumscribed carcinoma.
IMPRESSION: Cystosarcoma phylloides versus fibroadenoma.
HISTOPATHOLOGY: Malignant cystosarcoma phylloides.
NOTE: The calcifications in a cystosarcoma are described as plaquelike and coarse.
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Figure 4.57 HISTORY: A 66-year-old woman for screening mammography.
MAMMOGRAPHY: Right MLO (A) and CC (B) views. There is a relatively circumscribed, 1.2-cm, oval isodense mass in the 12 o’clock position of the right breast. Sonography did not reveal a solid or cystic lesion. Because of the size of the lesion and the slight indistinctness of some of its margins, it was regarded with a moderate degree of suspicion.
HISTOPATHOLOGY: Sclerosing adenosis (adenosis tumor).
NOTE: It is unusual for sclerosing adenosis to present mammographically as a circumscribed mass. Generally, the appearance is that of an ill-defined lesion with lobular-type microcalcifications.
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Figure 4.58 HISTORY: A 56-year-old woman with a history of uterine cancer who presents with a palpable left breast mass.
MAMMOGRAPHY: Left MLO (A) and spot magnification CC (B) views show the palpable mass to be round, very circumscribed, and isodense. Ultrasound (C) demonstrates the lesion to be hypoechoic, round, partially well defined, and to enhance the sound slightly. Because the sonographic features are not those of a simple cyst, but likely a complicated cyst, aspiration was performed. Thick turbid fluid was removed, and the lesion collapsed.
CYTOLOGY: Benign cyst fluid with histiocytes.
P.156

Figure 4.59 HISTORY: A 51-year-old woman for screening mammography.
MAMMOGRAPHY: Right MLO (A) and CC (B) views show a small, dense, round, relatively circumscribed mass at the 11 o’clock position (arrows). On the spot-compression CC view (C), the borders appear microlobulated, which is suspicious. This mass is associated with focal density containing some punctuate microcalcifications.
IMPRESSION: Microlobulated mass, suspicious for malignancy.
HISTOPATHOLOGY: Focal intraductal hyperplasia, adenosis, apocrine metaplasia, and microcalcifications.
P.157

Figure 4.60 HISTORY: A 49-year-old woman for screening mammography.
MAMMOGRAPHY: Left MLO (A) and enlarged MLO (B) views show the breast to be heterogeneously dense. There is a lobulated isodense mass at 12 o’clock (arrow) with relatively circumscribed margins. Ultrasound showed the mass to be solid. Based on these findings, core needle biopsy was performed.
HISTOPATHOLOGY: Sclerosing adenosis, fibrocystic change.
Figure 4.61 HISTORY: A 52-year-old woman for screening mammography.
MAMMOGRAPHY: Right MLO (A) and CC (B) views show scattered fibroglandular densities. There are two masses in the right breast. In the lateral area is a small lobulated mass that was stable from prior studies. At 6 o’clock is a lobular, isodense mass that appears circumscribed on spot compression (C). Ultrasound did not clearly demonstrate the lesion.
IMPRESSION: New solid circumscribed mass, right breast at 6 o’clock. Recommend biopsy.
HISTOPATHOLOGY: Fibrocystic changes with papillary apocrine metaplasia.
P.158

Figure 4.62 HISTORY: A 77-year-old woman with clear nipple discharge from the right breast.
MAMMOGRAPHY: Right CC (A) view demonstrates numerous dystrophic, coarse, and rodlike calcifications that are benign. In the right subareolar area medially is a small circumscribed mass (arrow). On the magnification CC view (B), the relatively circumscribed margin is seen, as well as vague, faint amorphous microcalcifications within the lesion.
IMPRESSION: Small subareolar mass, likely papilloma versus ductal carcinoma in situ. Recommend biopsy.
HISTOPATHOLOGY: Intraductal papilloma with atypical ductal hyperplasia.
P.159

Figure 4.63 HISTORY: A 44-year-old patient postlumpectomy and in radiation therapy for breast cancer.
MAMMOGRAPHY: Right ML (A) and CC (B) views show the postsurgical scar as well as clustered microcalcifications located at 3 o’clock (arrows). Core needle biopsy of the calcifications was performed. On the immediate postprocedure ML and CC images (C, D), a marker is noted at the biopsy site. Surrounding the clip is a lobulated isodense mass that has developed since the prebiopsy images.
IMPRESSION: Hematoma secondary to needle biopsy.
P.160

Figure 4.64 HISTORY: A 57-year-old woman who is recently postlumpectomy for breast cancer. The pretreatment mammogram has been performed to assess for residual carcinoma.
MAMMOGRAPHY: Left MLO view shows a large oval mass beneath the surgical scar. This mass has circumscribed margins and is isodense. Scattered benign calcifications are noted throughout the breast.
IMPRESSION: Normal postoperative change with hematoma/seroma at the lumpectomy site.
P.161

Figure 4.65 HISTORY: A 76-year-old woman 8 months after a lumpectomy for lobular carcinoma in situ in the left breast, with no palpable masses on physical examination.
MAMMOGRAPHY: Left MLO (A) and CC (B) views. There is a well-defined, moderately dense, round mass demonstrated on both views. This mass is situated directly beneath the surgical scar (arrow) from lumpectomy. Considering the history of recent biopsy in this region, a well-circumscribed hematoma was considered most likely.
IMPRESSION: Hematoma.
HISTOPATHOLOGY: Fibrous-walled cyst containing old blood.
Figure 4.66 HISTORY: A 67-year-old with a small palpable mass in left breast at 12 o’clock.
MAMMOGRAPHY: Left MLO (A) and CC (B) views show a round circumscribed mass in the superior aspect of the breast (arrow). Ultrasound (C) shows the mass to be hypoechoic, smoothly marginated, and located within the dermis. There is no separation between the skin line and the anterior surface of the lesion, suggesting a dermal origin.
IMPRESSION: Sebaceous cyst.
P.162

Figure 4.67 HISTORY: A 65-year-old gravida 1, para 1 woman for routine screening.
MAMMOGRAPHY: Right MLO (A) and enlarged (2÷) CC (B) views. There is scattered fibroglandular tissue present. In the right supra-areolar area, there is a well-circumscribed mass attached to the skin (arrow) (A). Coarse calcifications are present within the mass (A and B). The subcutaneous location of the mass is key to the diagnosis of a sebaceous cyst. Clinical examination also showed a firm nodule within the skin. The calcifications are dystrophic, related to chronically retained secretions.
IMPRESSION: Sebaceous cyst of right breast.
Figure 4.68 HISTORY: A 74-year-old woman with a small palpable mass in the parasternal area of the right breast.
MAMMOGRAPHY: Right CC spot view (A) shows a BB demonstrating the palpable lump, which is a small, dense, round circumscribed mass located superficially. On ultrasound (B), the mass is hypoechoic and smoothly marginated, and it is located in the subcutaneous area. There is an extension (arrow) from the mass to the skin, typical of the findings in a sebaceous cyst. Clinical exam confirmed the presence of an occluded pore in the skin over the lesion.
IMPRESSION: Sebaceous cyst.
P.163

Figure 4.69 HISTORY: A 46-year-old woman with an acute, very tender, indurated mass in the left subareolar area.
MAMMOGRAPHY: Bilateral MLO (A) and CC (B) views and left breast ultrasound (C). Asymmetry in the appearance of the breasts is present (A and B), with the left breast being more dense, particularly in the subareolar area, than the right. Beneath the left nipple is a well-circumscribed isodense mass (arrow). On ultrasound (C), the mass is complex, having an irregular wall and some internal echoes. The combination of findings on imaging and clinical examination is most consistent with a breast abscess.
IMPRESSION: Abscess.
NOTE: The lesion was aspirated of purulent material and resolved after treatment with antibiotics.
P.164

Figure 4.70 HISTORY: A 71-year-old woman who had been in a car accident several weeks earlier and sustained a puncture wound to the left breast. She presents now with a large painful mass.
MAMMOGRAPHY: Left MLO (A) and CC (B) views show a very large, isodense lobular mass that has well-defined margins. An air fluid level (arrow) is seen in the superior aspect of the mass. The clinical history and symptoms and the mammographic findings were most consistent with either an abscess or a large hematoma with air related to the puncture. The cavity was drained of purulent material.
IMPRESSION: Breast abscess secondary to trauma.
P.165

Figure 4.71 HISTORY: A 49-year-old woman with a positive family history of breast cancer, for screening.
MAMMOGRAPHY: Left CC (A) and MLO (B) views show a small oval mass in the lower-outer quadrant. On the enlarged images (C, D), the relatively circumscribed margins of the mass are seen. Ultrasound (E) shows the mass to be round and hypoechoic with irregular margins and surrounding hyperechogenicity. The sonographic features are much more suspicious than the mammographic findings.
IMPRESSION: Solid mass, highly suspicious for carcinoma.
HISTOPATHOLOGY: High-grade invasive ductal carcinoma.
P.166

Figure 4.72 HISTORY: A 63-year-old woman with a small palpable mass in the right breast.
MAMMOGRAPHY: Right MLO (A) and CC (B) views show a round, relatively circumscribed, high-density mass at 5 o’clock. On spot compression (C), the circumscribed border is seen, with slight indistinctness at the posterior edge. On ultrasound (D), the mass is very hypoechoic, taller than wide, and slightly irregular in contour. The high density of the mass on mammography and the sonographic features are very suspicious for malignancy.
IMPRESSION: Highly suspicious for carcinoma, BI-RADS® 5.
HISTOPATHOLOGY: High-grade invasive ductal carcinoma.
P.167

Figure 4.73 HISTORY: A 57-year-old woman with a palpable mass in the right breast at 9 o’clock.
MAMMOGRAPHY: Right MLO (A) and CC (B) views show a large mass at 9 o’clock that correspond to the palpable lesion. This mass is lobular and high density with microlobulated margins and is therefore worrisome for malignancy. Multiple small, lower-density, round masses are posterior to the lesion and may represent intramammary nodes or satellite lesions (arrows). Centrally at 6 o’clock is a second round mass (arrowheads), which on spot compression (C) is shown to have indistinct margins. Laterally at 8 o’clock is a third lobular mass (open arrow). Sonography of the lesions at 9 o’clock (D), 6 o’clock (E), and 8 o’clock (F) shows solid round and lobular masses with somewhat indistinct margins suspicious for carcinoma.
IMPRESSION: Multicentric carcinoma.
HISTOPATHOLOGY: Invasive ductal carcinoma, high grade at the three sites.
P.168

Figure 4.74 HISTORY: A 41-year-old woman with a palpable right breast mass.
MAMMOGRAPHY: Bilateral MLO (A) and CC (B) views show an obscured round mass (arrow) at the site of palpable abnormality. On spot compression (C), the borders remain obscured. Ultrasound (D) shows a markedly hypoechoic round mass with slightly irregular margins and acoustic enhancement. The low-level echoes, round shape, and slightly indistinct edges are suspicious for malignancy.
IMPRESSION: Mass, suspicious for carcinoma.
HISTOPATHOLOGY: Invasive ductal carcinoma.
P.169

Figure 4.75 HISTORY: A 76-year-old woman with a left palpable mass.
MAMMOGRAPHY: Left CC (A) view shows a lobular isodense mass marked with a BB. On spot compression (B), the mass is noted to have microlobulated margins, which is a suspicious finding. Ultrasound (C) shows the mass to be relatively circumscribed, round, and associated with increased transmission of sound. The finding could represent a fibroadenoma, circumscribed malignancy, or complicated cystic lesion. Because of the microlobulation and the somewhat rounded appearance on ultrasound, malignancy is most likely.
IMPRESSION: Microlobulated mass suspicious for carcinoma.
HISTOPATHOLOGY: Invasive ductal carcinoma with extensive mucinous features.
P.170

Figure 4.76 HISTORY: A 44-year-old woman for screening.
MAMMOGRAPHY: Left MLO (A) and CC (B) views show a lobular isodense mass at 6 o’clock (arrows). On spot compression (C), the mass is relatively well defined, but the edges are somewhat microlobulated. The mass had increased in size since the prior study. Because of the interval change and the margination, biopsy was recommended.
IMPRESSION: Microlobulated mass suspicious for carcinoma, BI-RADS® 4.
HISTOPATHOLOGY: Invasive ductal carcinoma.
Figure 4.77 HISTORY: A 60-year-old woman with an abnormal screening mammogram.
MAMMOGRAPHY: Right ML (A) and cleavage (B) views show a mass located far medially and posteriorly. The mass is oval, high density, and relatively circumscribed. Because of its posterior location and density, carcinoma is a likely possibility.
HISTOPATHOLOGY: Invasive ductal carcinoma.
P.171

Figure 4.78 HISTORY: A 46-year-old woman with a palpable mass in the upper-outer aspect of the left breast.
MAMMOGRAPHY: Left MLO (A) and CC (B) views show a large, high-density, lobular mass with relatively circumscribed margins. In some areas, the borders are somewhat indistinct. The differential diagnosis included phylloides tumor versus carcinoma.
IMPRESSION: Highly suspicious for malignancy, BI-RADS® 5.
HISTOPATHOLOGY: Medullary carcinoma.
Figure 4.79 HISTORY: A 49 year-old woman recalled from screening for a right breast mass.
MAMMOGRAPHY: Right ML view (A) shows a small round mass with microlobulated margins in the central aspect of the breast. On a spot digital image (B), the undulating border associated with microlobulation is evident and is suspicious for carcinoma.
IMPRESSION: Microlobulated mass, suspicious for carcinoma.
HISTOPATHOLOGY: Invasive ductal carcinoma, nuclear grade 2.
P.172

Figure 4.80 HISTORY: A 37-year-old gravida 1, para 1 woman with a positive family history of breast cancer and a palpable 2-cm lump in the left upper-outer quadrant.
MAMMOGRAPHY: Left MLO (A) and exaggerated CC lateral (B) views and ultrasound (C). There is a relatively well-circumscribed mass in the left upper-outer quadrant (arrow) (A and B). The mass is of medium to high density, and although it is relatively circumscribed, its borders are microlobulated, suggesting a malignant etiology. On ultrasound (C), the mass is hypoechoic with mixed echogenicity, and it has irregular borders (arrow). Such findings are more consistent with a malignant lesion than with a benign lesion such as a fibroadenoma.
IMPRESSION: Highly suspicious for primary carcinoma.
HISTOPATHOLOGY: Adenocarcinoma with 24 nodes negative.
P.173

Figure 4.81 HISTORY: A 73-year-old woman with a large palpable right breast mass.
MAMMOGRAPHY: Right MLO (A) and CC (B) views. There is a large, high-density, relatively circumscribed mass in the central aspect of the right breast. The borders of the mass are microlobulated and poorly defined in areas. A single area of coarse calcification (arrow) is present within the lesion. The differential diagnosis for the mass includes cystosarcoma phylloides, primary breast cancer, and a calcifying fibroadenoma; the favored diagnosis is a cystosarcoma phylloides because of the borders, large size, and the coarse calcification.
HISTOPATHOLOGY: Infiltrating ductal carcinoma.
P.174

Figure 4.82 HISTORY: Elderly patient who presents with a new palpable lump in the right breast.
MAMMOGRAPHY: Right MLO (A) and spot-magnification CC (B) views over the palpable lesion show an oval, relatively circumscribed isodense mass. On the spot view, some of the borders are very well defined, but others are more indistinct or obscured. Because of the partially indistinct margins, carcinoma is of concern. Sonography showed the mass to be solid.
IMPRESSION: Suspicious for carcinoma.
HISTOPATHOLOGY: Invasive ductal carcinoma.
Figure 4.83 HISTORY: A 74-year-old woman with a tender right breast and no palpable findings.
MAMMOGRAPHY: Right MLO (A) and CC (B) views and magnified image (C). There is a very-well-defined 1-cm mass in the right upper-outer quadrant. A magnified view shows the very-well-defined margins and fatty halo, suggesting a benign nature. Because of the location of the lesion, a primary consideration was an enlarged intramammary lymph node. Other considerations were fibroadenoma, cyst, and well-circumscribed malignancy.
IMPRESSION: Well-defined mass of low suspicion for malignancy.
HISTOPATHOLOGY: Adenoid cystic carcinoma.
NOTE: The prognosis for a patient with adenoid cystic carcinoma is excellent. Axillary node metastasis is rare, and distant metastases occur in less than 10% of cases.
P.175

Figure 4.84 HISTORY: A 69-year-old gravida 0 woman with adenocarcinoma in a right axillary node.
MAMMOGRAPHY: Right MLO view (A) and magnified image (B). The breasts show fatty replacement compatible with the age of the patient. There is relatively well-defined, moderately dense 2.5-cm mass in the subareolar area. A magnified image demonstrates fine irregularity of the borders of the lesion, rendering it suspicious in nature. Particularly in a patient of this age group, carcinoma is the most likely consideration.
IMPRESSION: Well-circumscribed carcinoma, possibly of medullary or mucinous type.
HISTOPATHOLOGY: Medullary carcinoma.
P.176

Figure 4.85 HISTORY: Series of screening mammograms on a postmenopausal woman.
MAMMOGRAPHY: Initial bilateral MLO and right CC views (A, B), MLO and right CC views 1 year later (C, D), and bilateral MLO and right CC views (E, F) 2 years later. On the initial study, a small, isodense, relatively circumscribed mass is noted at 10 o’clock in the anterior third of the right breast (arrows). No additional evaluation was performed. On subsequent study at 1 (C, D) year, the mass has increased in size and density.
On subsequent study at 2 years (E, F), the mass has increased in size and density. Because of the change on the final study, biopsy was performed.
IMPRESSION: Suspicious for carcinoma. BI-RADS® 4.
HISTOPATHOLOGY: Intracystic papillary carcinoma.
NOTE: Papillary carcinoma is one of the types of cancer that tends to be well defined. On the initial study, further workup—including spot compression and ultrasound—should have been performed. Any increase is sign of a circumscribed mass and warrants biopsy if the mass is not a cyst.
P.177

P.178

Figure 4.86 HISTORY: A 62-year-old woman with a palpable left breast mass.
MAMMOGRAPHY: Left CC (A) view shows a large, very dense round mass in the center of the breast. The borders are slightly indistinct in areas, but the mass is relatively circumscribed. Sonography (B) reveals the mass to be isoechoic, rounded, and well defined. Based on the slight indistinctness of the margins on mammography and the rounded appearance on ultrasound, malignancy of concern. Biopsy was performed.
IMPRESSION: Solid circumscribed mass, suspicious: carcinoma versus fibroadenoma versus phylloides tumor.
HISTOPATHOLOGY: Intracystic papillary carcinoma.
NOTE: Sometimes on ultrasound, the cystic and solid components of an intracystic neoplasm are evident. In other cases, as in this patient, the tumor completely fills the cyst cavity and the fluid is no longer evident. (Case courtesy of
Dr. Axel Ongre, Oslo, Norway.
)
P.179

Figure 4.87 HISTORY: An 87-year-old woman with a series of screening mammograms.
MAMMOGRAPHY: Left CC views in 1989 (A), 1990 (B), 1992 (C), and 1995 (D). There is a dense, round, circumscribed mass in the left inner quadrant on the initial study (A). This was not further evaluated and decreased in size on the study 2 years later (B). It remained stable the next year (C) and subsequently increased in size and density on the study 3 years later. At this point, it was excised.
HISTOPATHOLOGY: Mucoepidermoid carcinoma.
NOTE: Although it is rare for a breast cancer to decrease in size, those with a mucinous component may do so. On the initial study, further evaluation should have been performed because of the suspicious density of the lesion. (Case courtesy of
Dr. Thomas Poulton, Canton, Ohio.
)
Figure 4.88 HISTORY: A 47-year-old woman with a history of carcinoma of the fallopian tube.
MAMMOGRAPHY: Right coned-down CC view shows heterogeneously dense tissue. There is an oval, dense, relatively circumscribed mass located medially in the anterior third of the breast. The mass was not cystic on ultrasound. Because of the indistinct posterior edge, biopsy was performed.
IMPRESSION: Mass, slightly indistinct. Recommend biopsy.
HISTOPATHOLOGY: Metastatic carcinoma from the fallopian tube.
P.180

Figure 4.89 HISTORY: A 61-year-old woman with a history of ovarian cancer and a firm lump in the right breast.
MAMMOGRAPHY: Right CC view. There is a 2-cm, well-defined radiodense mass (arrow) in the right breast at 12 o’clock. There is a fatty halo around a portion of the lesion. The primary differential diagnoses include cyst, fibroadenoma, well-defined primary breast cancer, and metastasis to the breast. In a patient of this age, a fibroadenoma would very likely have begun to calcify. Therefore, malignancy, either primary or secondary, is more likely.
HISTOPATHOLOGY: Adenocarcinoma metastatic from ovarian primary.
NOTE: Metastatic disease to the breast may present as a solitary well-defined mass, usually located in the subcutaneous fat layer. More common primary sites for metastases to the breast are melanoma, lymphoma, sarcoma, lung, and gynecologic cancers.
P.181

Figure 4.90 HISTORY: A 61-year-old woman for routine screening mammography. She was not on hormonal replacement therapy.
MAMMOGRAPHY: Bilateral CC views (A) and CC views 1 year earlier (B). On the current study (A), there are numerous dense, round, circumscribed masses in both breasts. These masses had developed since the prior study. Multiple cysts are included in the differential for round masses; however, the postmenopausal state of the patient and the lack of hormonal replacement therapy make cysts an unlikely etiology. Ultrasound showed solid masses.
IMPRESSION: Numerous new round masses favor metastases or lymphoma.
HISTOPATHOLOGY: Non-Hodgkin’s lymphoma.
P.182

Figure 4.91 HISTORY: A 40-year-old woman with history of melanoma, for screening mammography.
MAMMOGRAPHY: Bilateral MLO (A) and CC (B) views show multiple abnormalities bilaterally. In the left axillary tail is a spiculated mass, appearing more vague on the exaggerated CC lateral (C) view. This was the site of lymph-node dissection following the prior melanoma resection. On the right, there are three round circumscribed masses, one of which is located in the axilla. These were solid on sonography. Although these could be benign—lymph nodes or fibroadenomata—metastatic melanoma is a likely possibility.
IMPRESSION: Left axillary node dissection scar, metastatic melanoma to the right breast.
HISTOPATHOLOGY: Metastatic melanoma, right breast.
P.183

Figure 4.92 HISTORY: A 45-year-old gravida 3, para 3 patient with a history of lymphoma and a palpable nodule in the right retroareolar area.
MAMMOGRAPHY: Right MLO views from April 1989 (A) and July 1989 (B), after chemotherapy for lymphoma. On the initial study, there are three bean-shaped, very-well-circumscribed nodules (straight arrows) in the right breast, as well as a partially circumscribed, round isodense mass (curved arrow) in the subareolar area. The subareolar mass was shown to be a simple cyst on ultrasound. The bean-shaped nodules are most consistent with adenopathy related to the patient’s known lymphoma. Following chemotherapy (B), the nodes decreased in size to a normal range. Mammography may be useful for monitoring the response to chemotherapy in patients in whom there is axillary or intramammary adenopathy.
IMPRESSION: Adenopathy secondary to lymphoma.
P.184

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