[Significance of proliferative breast lesions around breast cancers].

To clarify the relationships between benign proliferative diseases and cancers of the breast, 44 cases treated with breast conserving surgeries were analyzed histopathologically. Intraductal hyperplasia, sclerosing adenosis and adenosis were more frequently seen in cancerous than non-cancerous breasts, with a statistically significant difference. Additionally, histologies of some intraductal spread in carcinomas were identical to those of atypical hyperplasias. Further studies should be undertaken, and definitions of atypical hyperplasia, especially in cancerous breasts, should be critically redefined.