Background: The cytologic features of secretory breast carcinoma were first described as recently as 1986. Only one other report of fine needle aspiration (FNA) diagnosis of secretory breast carcinoma in a male has been published, in 1994.
Case: A 33-year-old male with a unilateral breast mass present for at least 10 years underwent FNA aspiration biopsy, excisional biopsy and mastectomy. FNA cytology findings demonstrated marked overlap with features described as characteristic of lactation changes.
Conclusion: Secretory breast carcinoma is a rare, usually well differentiated neoplasm that occurs most often in young, reproductive-age women and less often in girls and is exceedingly rare in men. The cytologic features that have been described for secretory carcinoma have emphasized the morphologic distinction from other types of breast carcinoma but have not stressed the potentially significant resemblance of this neoplasm to benign epithelial proliferative lesions, particularly lactational changes/lactating adenoma. This case illustrates features almost completely morphologically identical to the well-defined features of lactational change and emphasizes that the clinical information is ultimately important in this distinction.