Benign and malignant conditions affect the male breast to a much lesser degree than the female breast, and mammography is of help in the differentiation of some of these lesions. Although mammography, and particularly the craniocaudal (CC) view, may be difficult to perform unless the breast is enlarged, the mediolateral oblique (MLO) view can generally be quite satisfactorily obtained. Ultrasound may be a helpful modality in the evaluation of male breast enlargement (1), but it does not replace mammography, particularly in the evaluation of a unilateral breast mass (2).
A variety of diseases can occur in the male breast, but the most common diagnoses are gynecomastia and breast cancer. In a review of 236 male patients who underwent mammography, Günhan-Bilgen et al. (3) found that 206 had gynecomastia, 14 had primary breast cancer, 3 had metastases, and 13 had other benign lesions (including hematomas, fat necrosis, inclusion and sebaceous cysts, and lipomas). In another series of 263 men with breast abnormalities, Cooper et al. (4) found that the majority, 81%, had gynecomastia on mammography.
Gynecomastia
Gynecomastia is the development of a male breast into the shape of a female breast and is clinically evident as a firm palpable breast mass in the subareolar area. Gynecomastia occurs most commonly in adolescent boys and in men older than 50 years, and the condition represents about 85% of breast masses in men (5). The etiologies of gynecomastia include (a) hormonal (related to an imbalance in estradiol-testosterone levels or to dysfunction of the adrenal, thyroid, or pituitary glands), (b) systemic (in cirrhosis, chronic renal failure with hemodialysis, chronic obstructive pulmonary disease, and tuberculosis), (c) drug induced (secondary to exogenous estrogens, digitalis, cimetidine, antihypertensives, ergotamine, tricyclic antidepressants, and marijuana), (d) tumors (particularly of testicular, pituitary, and adrenal origin or secondary to hepatomas or lung cancers), and (e) idiopathic.
The normal male breast contains subcutaneous adipose tissue and a few rudimentary ducts beneath the nipple. The appearance is similar to that of the prepubertal girl. Histologically, three forms of gynecomastia are noted: (a) florid, which usually occurs over a short duration and is seen to have an increase in the ducts with proliferation of the epithelium, edema, and an increase in the stroma and fat; (b) fibrotic, which is more chronic and seen in elderly men who have dilated ducts without an increase in stroma or edema; and (c) intermediate (5).
The most common mammographic appearance of gynecomastia (54%) in a series by Chandrakant and Pareck (5) was that of mild prominence of the subareolar ducts (Figs. 11.1 and 11.2). Dershaw (6) found the most common presentation of gynecomastia as a triangular or flame-shaped density symmetrically situated behind the nipple. The appearance, however, may range to diffuse ductal enlargement or even to a homogeneously dense breast having the appearance of that of a young woman (Figs. 11.3,11.4,11.5,11.6,11.7,11.8,11.9). The condition may be unilateral or bilateral. Günhan-Bilgen et al. (3) found that 55% of cases of gynecomastia were unilateral and 45% were bilateral. Cooper et al. (4) found that 72% of patients with gynecomastia had unilateral findings. Of importance in suggesting the diagnosis of gynecomastia on mammography is that the increased density or prominent ductal pattern be situated directly beneath the subareolar area and radiate out in a fan shape, as would be expected for the distribution of the ducts.
In most cases, mammography alone is sufficient as an imaging evaluation of the patient with gynecomastia. The findings of uniform subareolar parenchymal density in the patient with breast enlargement are typical of gynecomastia. Sonography may be helpful in questionable cases as it depicts normal-appearing ductal structures and no mass. Some authors have suggested sonography as the first-line imaging (7) in patients with suspected gynecomastia, although this is not a common practice.
Benign masses that have been described in the male breast include inclusion or sebaceous cysts (Fig. 11.10), abscesses, hematomas, fat necrosis (Fig. 11.11), enlarged
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lymph nodes (5), intraductal papillomas, and fibroadenomas (2). The mammographic manifestations of these masses are similar to those found in the female breast. Because of the need for progesterone for lobular development, genetically normal men do not develop lobules and do not have the lesions that occur in the lobule. Therefore, fibrocystic changes and lobular carcinomas do not occur in genetically normal men. Instead, the parenchymal lesions that occur in the man are ductal in origin: gynecomastia and ductal carcinomas.
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Figure 11.1 HISTORY: A 45-year-old man with a tender left breast mass. MAMMOGRAPHY: Left (A) and right (B) CC views demonstrate flame-shaped densities in both subareolar areas. The findings are more prominent in the left breast than in the right. IMPRESSION: Unilateral gynecomastia. |
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Figure 11.2 HISTORY: A 47-year-old man reporting left breast pain. MAMMOGRAPHY: Bilateral MLO (A) and CC (B) views show breast enlargement with subareolar flame-shaped densities, on the left greater than the right, consistent with bilateral gynecomastia. IMPRESSION: Bilateral gynecomastia. |
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Figure 11.3 HISTORY: A 63-year-old man with soreness and a tender 3-cm lump in the left breast. MAMMOGRAPHY: Bilateral views show marked asymmetry in the appearance of the breasts. The left breast is larger and markedly more dense than the right. On the right, only rudimentary ducts are present. The density in the left is radiating back from the nipple and is most consistent with gynecomastia. IMPRESSION: Unilateral gynecomastia. |
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Figure 11.4 HISTORY: A 38-year-old man with breast enlargement. MAMMOGRAPHY: Bilateral MLO (A) and CC (B) views show generalized enlargement bilaterally. There is diffuse increase in parenchymal density extending from the subareolar regions bilaterally. IMPRESSION: Bilateral gynecomastia. |
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Figure 11.5 HISTORY: A 78-year-old man with history of bomb exposure in Hiroshima and a past medical history of multiple carcinomas. He had been treated recently with estrogen therapy for prostate cancer. MAMMOGRAPHY: Bilateral MLO (A) and CC (B) views show enlargement of both breasts with increased parenchyma bilaterally. Also noted are extensive dermal calcifications. IMPRESSION: Bilateral gynecomastia. |
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Figure 11.6 HISTORY: A 61-year-old man with right breast tenderness and induration. MAMMOGRAPHY: Bilateral MLO (A) and CC (B) views show fatty enlargement of both breasts. In addition, on the right, there is diffuse parenchymal density extending from the nipple posterolaterally, typical of unilateral gynecomastia. IMPRESSION: Unilateral gynecomastia. |
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Figure 11.7 HISTORY: A 38-year-old man with liver failure and right breast enlargement. MAMMOGRAPHY: On bilateral MLO (A) and CC (B) views, there is bilateral ductal prominence on the right greater than the left, consistent with gynecomastia. Findings of prominent pectoralis major muscle and relatively small breasts suggest a male patient. IMPRESSION: Gynecomastia, right greater than the left. |
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Figure 11.8 HISTORY: A 61-year-old man on steroids with left breast enlargement. MAMMOGRAPHY: Bilateral MLO (A) and CC (B) views show generalized breast enlargement. There is parenchymal density in the subareolar areas bilaterally, seen on the left to a greater degree than on the right, consistent with gynecomastia. IMPRESSION: Gynecomastia. |
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Figure 11.9 HISTORY: A 21-year-old man who presented with unilateral breast enlargement. He stated that he had sustained blunt trauma to the right chest 2 weeks earlier; no bruising, mass, or tenderness was found on physical examination. MAMMOGRAPHY: Bilateral MLO views show striking asymmetry in the appearance of the breasts. The left breast has a normal appearance for a man, with minimal fat and rudimentary ductal structures noted. The right breast is striking enlarged and is dense and glandular, having the appearance of an adult female breast. IMPRESSION: Unilateral gynecomastia. |
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Figure 11.10 HISTORY: A 32-year-old man presenting with a large, tender palpable right breast mass. MAMMOGRAPHY: Left (A) and right (B) MLO views show marked asymmetry in the appearance of the breasts. The left breast has a normal appearance for a male patient: prominent pectoralis major muscle and rudimentary ducts. There is a very large, circumscribed, high-density oval mass in the right breast. An occluded inflamed pore was noted on the skin overlying the mass. IMPRESSION: Sebaceous cyst. NOTE: The mass was drained and was a sebaceous cyst. This has the appearance of the “egg in the breast” in a male patient, which is typical for a large sebaceous cyst. |
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Figure 11.11 HISTORY: A 41-year-old man who had been bitten by a horse on the left breast 6 months earlier, presenting with a firm mass in the upper inner quadrant. MAMMOGRAPHY: Bilateral MLO (A) and enlarged left CC (B) views and ultrasound (C). There is some prominent ductal tissue in both subareolar areas (open arrows) (A and B), consistent with a mild degree of gynecomastia. On the left, near the chest wall, there is a radiolucent, circumscribed encapsulated mass (curved arrows) (A and B) having the characteristic appearance of an oil cyst. Sonography (C) shows this mass to be relatively anechoic, with good through-transmission of sound and a well-defined back wall. These findings corresponded to the area of palpable abnormality. Incidentally noted also are extensive skin calcifications. IMPRESSION: Large oil cyst secondary to previous trauma. HISTOPATHOLOGY: Fibrous walled cyst, fat necrosis. |
Carcinomas of the male breast accounts for about 0.9% of all breast cancers (8). The disease is more common in men older than 60 years, but breast cancer has been seen rarely in young men. Most patients present clinically with a palpable breast lump (9). Factors that increase the risk of male breast cancer include advanced age, positive family history, Jewish origin, black race (10), altered estrogen metabolism, exogenous estrogens, infectious orchitis, Klinefelter syndrome, and radiation to the chest (11). The BRCA2 mutations are believed to account for the majority of inherited breast cancers in men (12,13).
In reviewing National Cancer Institute Surveillance, Epidemiology, and End Results (SEER) data from 1973 to 1998, Giordano et al. (14) found that the incidence for male breast cancer increased significantly from 0.86 to 1.08 per 100,000 population. In comparison with women, men had a higher median age at diagnosis, were more likely to have lymph node involvement, had a more advanced stage at
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diagnosis, and had tumors positive for estrogen and progesterone receptors. Relative survival rates for men and women were similar for similar stages and grade of tumors.
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Figure 11.12 HISTORY: A 62-year-old man who presented with palpable thickening in the right breast. MAMMOGRAPHY: Bilateral MLO (A) and CC (B) views show marked asymmetry in the appearance of the breasts. The right breast is noted to contain dense dilated ducts in the subareolar lesion. However, these ducts are associated with extensive pleomorphic microcalcifications, better seen on magnified CC (C) and ML (D) views. The presence of the microcalcifications is highly suspicious for malignancy. IMPRESSION: BI-RADS® 5, highly suspicious for malignancy. HISTOPATHOLOGY: DCIS. |
In comparison with breast cancers in women, when screening mammography is performed and detects in situ cancers, the rate of male ductal carcinoma in situ (DCIS) is small. DCIS accounts for about 5% of all male breast cancers (15), whereas in women, it often represents about one fourth of breast malignancies. DCIS in male patients presents with malignant microcalcifications associated with dilated ducts that are extensive (Fig. 11.12) and that present as palpable thickening or a nipple discharge. Although sex differences have been found with respect to tumor characteristics, sex has not been found to be a significant predictor of survival (16).
On mammography, male breast cancer usually presents as a spiculated mass, like scirrhous cancer of the female breast. A majority of male breast cancers are located in an eccentric position relative to the nipple, and they present as noncalcified masses (3). Calcifications may occur, but they are usually larger and fewer in number than those found in cancers of the female breast (5). Male breast carcinoma is distinguished from gynecomastia by its eccentric location, spiculation, microcalcifications, and secondary features (Figs. 11.13 and 11.14), such as skin or nipple retraction (17). Male breast cancers may also present as more circumscribed masses (Figs. 11.15 and 11.16) when the etiology is a specialized type of malignancy, such as the papillary, medullary, or mucinous types. If, however, gynecomastia presents in an eccentric location (6), it may not be readily distinguished from carcinoma, and biopsy is warranted.
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Figure 11.13 HISTORY: An 80-year-old man with fixed right breast mass. MAMMOGRAPHY: Left (A) and right (B) CC views show a normal-appearing left breast and a large dense microlobulated mass in the posterolateral aspect of the right breast. This mass is not associated with the subareolar area and is eccentric relative to the nipple, all features that are suspicious for malignancy. There is also associated skin thickening laterally (arrow). IMPRESSION: Highly suspicious for carcinoma. CYTOLOGY: Carcinoma. |
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Figure 11.14 HISTORY: A 55-year-old male patient who presents with left nipple retraction and a firm palpable mass. MAMMOGRAPHY: Bilateral MLO (A) and CC (B) views show a normal-appearing right breast and a mass in the subareolar area of the left breast. On the left CC spot-magnification view (C), the mass is spiculated and is associated with nipple retraction and mild skin thickening. IMPRESSION: Highly suspicious for carcinoma. HISTOPATHOLOGY: Invasive ductal carcinoma. |
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Figure 11.15 HISTORY: Male patient with an enlarged left breast and a palpable mass laterally. MAMMOGRAPHY: Left MLO (A) and CC (B) views show a mild degree of gynecomastia, characterized by subareolar ductal prominence. There is also a round, dense, slightly indistinct mass in the upper outer quadrant (arrow), suspicious for carcinoma. IMPRESSION: Gynecomastia and probable carcinoma. HISTOPATHOLOGY: Invasive ductal carcinoma. |
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Figure 11.16 HISTORY: An 80-year-old man with a firm mass beneath the left nipple. MAMMOGRAPHY: Left ML view (A) and magnified image (B). The breast is somewhat enlarged but fatty and not containing prominent ductal tissue, as would be found in gynecomastia. In the subareolar area, there is a well-defined high-density mass with slight microlobulation of the margins, suggesting a suspicious nature. IMPRESSION: Mass in the left breast, highly suspicious for carcinoma. HISTOPATHOLOGY: Medullary carcinoma. NOTE: The scalloping of the edges of this lesion (B) and the high density are the features suggestive of malignancy. (Case courtesy of Dr. Luisa Marsteller, Norfolk, VA. ) |
References