Lobular cancerization: incidence and differential diagnosis with lobular carcinoma in situ of breast.

A series of 120 breast biopsies and mastectomy specimens originally diagnosed as carcinoma was reviewed in order to emphasize the differences between lobular carcinoma in situ and cancerization of lobules. Criteria for differential diagnosis between the two types of lobular lesion are proposed. In the reviewed material 15 (12.5%) cases of lobular carcinoma in situ and 64 (53.3%) of lobular cancerization were found. The carcinoma in situ usually co-existed with other types of breast carcinoma, such as intraductal carcinoma, cancerization and invasive carcinoma of different types.