Paget's disease in gynecomastia: immunohistochemical study of a case.

A case of Paget's disease and gynecomastia in a 70-year-old man is reported. Paget's disease was connected to an intraductal carcinoma, and the immunohistochemical study revealed similar positivity for cytokeratin A, carcinoembryonic antigen and epithelial membrane antigen in Paget cells and intraductal neoplastic cells whereas Paget cells resulted negative for cytokeratin B and C. The study using monoclonal anti-cytokeratin A (35 beta H11), B (34 beta E12) and C (34 beta B4) could represent a good tool, supporting the theory of a ductal origin of Paget cells. A review of the literature has shown the rarity of Paget's disease in the male breast and revealed only two previous reports with an associated gynecomastia, in 2 patients with Klinefelter's syndrome and infiltrating breast carcinoma.