Fibrocystic condition and "at risk" lesions in asymptomatic breasts: a morphologic study of postmenopausal women.

A series of postmenopausal women who had died without noticing any clinical breast disease in their anamnesis (100 cases, age range 46-90 years, average age 62 years) were submitted to bilateral subcutaneous mastectomy during autopsy in order to evaluate the morphologic profile of asymptomatic mammary glands, at different ages. Submacroscopic changes were found and removed to be processed for histology. Results were as follows: a) 46% of cases did not show any change; b) 54% of cases showed benign changes, namely a fibrocystic condition; c) 14% of cases had in addition epithelial lobular hyperplasia with low grade atypia and d) 3% of cases showed atypical borderline lobules (ABL), i.e., terminal ductal-lobular units characterized by severe epithelial atypia. Such lesions cannot be easily distinguished from "in situ" carcinoma, and are currently considered at morphologic risk for subsequent cancer when found in breast biopsies. Our data show that: 1) ABL do not represent a common finding in women who never complained of breast pathology during life; 2) ABL are not related to older age; 3) Fibrocystic condition is quite frequent at subclinical levels also in asymptomatic aging women. The latter statement confirms the opinion that fibrocystic condition should be considered as a common "functional" change. On the contrary, the rarity of ABL gives us a further indirect evidence of their possible precancerous significance. The risk of subsequent development of cancer from the collateral mammary gland could be theoretically higher when ABL are found in breast biopsies of fertile and premenopausal women, who have a longer period of life expectation.