Breast masses in males: multi-institutional experience on fine-needle aspiration.

Male breast masses are uncommon pathologic findings. They are rarely aspirated, resulting in limited cytopathologic experience. The following study describes the cytopathology of male breast lesions from data collected for a period of 10 yr from three large institutions. A total of 14,026 breast aspirations were performed of which 614 were from male patients. All cases were reviewed and correlated with the appropriate clinicopathologic follow-up. The FNA diagnoses were as follows: benign, 427 cases (gynecomastia 353, fat necrosis 21, miscellaneous 53); malignant, 32 cases (ductal carcinoma nos 15, metastatic tumors 17); and atypical/suspicious, 61 cases. Ninety-four cases were nondiagnostic due to scant cellularity. Male breast aspirates accounted for 4.3% of the total breast FNAs performed. The clinicopathologic follow-up in both the benign and malignant categories showed 100% correlation. The overall sensitivity was 95.3%, specificity was 100%, and diagnostic accuracy was 98%. A relatively high specimen unsatisfactory rate was seen (>15%). The commonest cytopathologic diagnosis was gynecomastia, followed by ductal carcinoma. Florid duct atypia in gynecomastia may mimic adenocarcinoma, necessitating a higher threshold for cytopathologic interpretation for malignancy in males.