Paget's disease of the nipple. Alternative management in cases without or with minimal extent of underlying breast carcinoma.

Six cases of Paget's disease of the nipple without clinical or mammographic evidence of a breast mass are described, two without underlying carcinoma of duct origin, and four with very limited duct carcinoma in situ of the most distal lactiferous ducts. Ultrastructural and immunohistochemical studies on these cases demonstrate that Paget cells arise in situ and invalidate the prevalent "epidermotropic" theory of histogenesis. Paget's disease of the nipple is considered to be an independent in situ carcinoma and part of the general phenomenon of multicentricity in breast cancer. A therapeutic option of conservative surgical intervention and follow-up is described for five of these select patients, all of whom are presently without evidence of disease with an average follow-up of 50 months (range, 30-69 months).