Klinefelter's syndrome associated with breast carcinoma and Paget's disease of the nipple.

We describe a patient with Klinefelter's syndrome associated with multi-focal breast carcinoma and Paget's disease of the nipple. Reviewing the 16 previously documented cases in the world literature, it is apparent that patients with this syndrome have an increased incidence of breast carcinoma. There is no evidence to date to suggest that such tumour is morphologically or biologically different from breast cancer in females and normal men.