Abstract
We report a rare case of nipple adenoma. A 38-year-old woman was examined for a small hard mass in the right mammary nipple. Cytological findings showed numerous duct epithelial cells with papillary clusters and a two-cell pattern mixed with myoepithelial cells. Apocrine metaplasia-like cells were observed, but with little atypia, yielding a definitive diagnosis of a benign tumor. This case demonstrates the importance of checking the appearance of atypia, cell cohesiveness, and two-cell pattern of duct epithelium to differentially diagnose cases such as this from Paget’s disease or invasive duct carcinoma.
