Most symptomatic men were referred for a palpable mass in our series. 

Benign pathology was predominant (four abscesses, two epidermal inclusion cysts, one hematoma and one myofibroblastoma).

SUBAREOLAR ABSCESS

A subareolar abscess is a localized infection secondary to ductal ectasia which tends to recur unless treated by excision of both the abscess and duct. Common clinical features include pain, nipple swelling, and nipple discharge.  

Because of their predilection for a subareolar location, breast abscesses can simulate gynecomastia.

Four cases of subareolar abscess were seen in our series. At mammography, all appear as an obscured or partially obscured borders subareolar mass. At US, it appears as an incompletely circumscribed mass containing complex fluid (Fig. 1, Fig. 2 ). 

EPIDERMAL INCLUSION CYST

Epidermal inclusion cyst is a skin lesion. It presents as a round well circumscribed dense mass. At US, it appears as completely circumscribed mass containing complex fluid.  The cysts are composed of laminated keratin with a wall of epidermis. If the cysts rupture, an inflammatory reaction ensues and indistinct margins of the ruptured cysts make it difficult to distinguish them from malignant lesions at mammography.

In our series, there were two cases of epidermal inclusion cysts. Both had the typical sonographic appearance ( Fig. 3 ).

HEMATOMA

Hematoma is benign processe usually related to breast trauma. 

Acutely, hematomas may manifest as atypical masses associated with trabecular accentuation and skin thickening; the mammographic appearance can simulate breast cancer or a breast abscess. Chronic hematoma have a variable mammographic appearance, which can include persistent oval masses; foci of architectural distortion, and dystrophic calcifications.

In our series atypical mass associated with trabecular accentuation and skin thickening was seen in the single case ( Fig. 4 ).

MYOFIBROBLASTOMA

Myofibroblastoma is a rare, benign stromal tumor that typically occurs in men in the 6th to 7th decades of life. Myofibroblastoma occurs sporadically and manifests clinically as a freely moveable, solitary, palpable, firm mass.


Mammographic features include a welldefined, round to ovoid, dense mass that usually ranges from 1 to 4 cm in size. There are no calcifications. US displays a solid, well-circumscribed, homogeneously hypoechoic mass. 

The favored treatment is surgical resection. 

In the single case in our series, at mammography, appears as a well-circumscribed, ovoid mass. US image shows an ovoid, pseudoencapsulated, hypoechoic mass with central vascularity ( Fig. 5 ).

Regarding malignant disease, 4 cases of invasive ductal carcinoma including a case of papillary carcinoma (a well-differentiated atypical subtype) and a breast metastases of an urothelial tumor.

MALE BREAST CANCER

Male breast cancer is substantially less common than gynecomastia and accounts for 0.7% of all cases of breast cancer. It manifests clinically as a hard, fixed, painless mass. Bloody nipple discharge is common.

Risk factors for breast cancer include Klinefelter syndrome, BRCA1 or BRCA2 mutation, a family history of breast cancer in a first-degree male or female relative, hyperestrogenism, advanced age, a history of chest irradiation, and a history of exogenous estrogen treatment for feminization purposes.

In men, breast cancer is typically diagnosed at an age approximately 5–10 years older than the age at which it is diagnosed in women. In addition, men usually present at a more advanced stage of cancer than do women owing to a delay in diagnosis. 

Infiltrating ductal carcinoma is the most common histologic subtype of male breast cancer. Other less common subtypes include ductal carcnoma in situ, infiltrating mammary carcinoma with mixed features and invasive papillary carcinoma. Metastasis to the breast from an extramammary primary malignancy is extremely rare. It results from hematogenous spread and is usually seen in patients with widespread disease.

It is important to recognize that gynecomastia occurs central to the nipple (Fig. 6 ), whereas malignancies tend to be eccentric in location.

At mammography, most invasive carcinomas will appear as a high-density, irregular, retroareolar mass with spiculated, lobulated, or microlobulated margins. One notable imaging feature of male breast carcinoma is that microcalcifications are absent in a significant number of

cases. US features include a solid, hypoechoic, subareolar mass that is eccentric to the nipple, with an irregular shape and a spiculated or microlobulated margin. Secondary features include skin thickening, nipple retraction, and axilary adenopathy.

In our series, there were five cases of male breast cancer, and were not evident calcifications, nipple retraction, skin thickening or axillary lymphadenopathy. The carcinoma manifested as a nodular lesion, with four lessions being eccentric (Fig. 7) and one central to the nipple  (Fig. 9). Four were irregular mass with microlobulated margins (Fig. 8,  Fig. 11) and one was well-defined associated with a complex cyst with mixed solid and cystic morphologic features at US ( Fig. 10 ).