Abstract

The relationship between fibrocystic disease and carcinama of the breast has teen discussed for many years. Thongu it is difficult to determine which of the histologic features of cystic disease has precancerous potential, recent reviews stress the possible relationship between atypical epithelial hy-perplasia and carcinoma. Author studied 51 radical mastectomized specimens of breast cancer and 44 excised specimens of fibrocystic disease, to compare the frequency of atypical hyperplasia of ducts and lobules in the benign and malignant lesions. The results are as follows: 1) Cystic change and sclerosing adenosis were the most common types of fibrocystic disease, and infiltrating scirrhous carcinoma was the most common type of breast cancer. 2) Apocrine metaplasia, ductal papillomatosis, lobular hyperplasia and sclerosing adenosis were more commonly seen in fibrocystic disease whereas atypical ductal and atypical lobular hyperplasia were common in cancer. The degree of atypia was severe in breast cancer. 3) Among fibrocystic disease, atypical ductal hyperplasia was frequently seen in the epithelial hyperplasia type. Among breast cancers, infiltrating comedo-carcinoma was frequently associated with atypical lesion of the duct. 4) Atypical lobular hyperplasia was frequently observed in the breasts of lobular carcinoma. However, the occurrence of atypical lobular hyperplasia in fibrocystic disease was rare.