The male breast and malignant neoplasms. Diagnosis by aspiration biopsy cytology.

Fine-needle aspiration biopsy is now an established procedure for the evaluation of breast masses in women. On the other hand, there are only occasional reports of aspirates from male breast masses. During the past 19 years from more than 14,000 mammary aspirates, the authors examined the aspiration biopsy cytology (ABC) from 14 cases of malignant mammary tumors in men. There were ten infiltrating ductal carcinomas, one mucinous carcinoma, two metastatic carcinomas, and one leiomyosarcoma. The cytologic and clinicopathologic feature of these cases are presented. Because these specimens can be readily differentiated from gynecomastia, aspiration biopsy is recommended as the initial procedure for all breast masses in men.