Well defined masses in the breast.

The authors retrospectively reviewed 118 well defined breast masses. Over 9% proved to be neoplastic or to represent lesions that are associated with a greater than normal risk of developing carcinoma. Thirty four examples of well defined masses representing a great variety of lesions are illustrated. The authors conclude that well defined breast masses warrant more careful examination and followup than they presently receive because of the greater than expected incidence of carcinoma and premalignant states.