Sclerosing adenosis in the breast of a man with pulmonary oat cell carcinoma: report of a case.

A case of sclerosing adenosis of the male breast is reported. This very unusual lesion was found at autopsy in a man with pulmonary oat cell carcinoma. In females, sclerosing adenosis is a well-characterized entity. In males, however, it does not normally occur because of the physiologic lack of lobular development. The possible pathomechanism of this lesion is briefly discussed, with an emphasis on presumed lobular stimulation by tumor-elaborated ectopic hormone.