Immunohistochemical analysis of estrogen and progesterone receptors in benign breast diseases.

Surgical specimens of 62 patients with fibrocystic disease, 39 with fibroadenoma and 11 with intraductal papilloma were evaluated with ER-ICA and PgR-ICA methods. Positive nuclear staining was only observed in the epithelial components. The myoepithelium, myofibroblasts, fibroblasts and the so called apocrine epithelium, however, did not contain steroid receptors. Some steroid receptor negative cases occurred among the atrophic and non-proliferating fibrocystic diseases. In the proliferating benign alterations, particularly in those considered preneoplastic, e.g. radial scar, ductal and lobular atypical epithelioses, such as carcinoma lobulare in situ and florid intraductal papilloma there was a positive staining for estrogen receptor and progesterone receptor in the epithelial cells. Authors' results seem to serve as a theoretical basis for the hormonal influence of precarcinomatous cases and to explain the success of antisteroid therapy in patients with fibrocystic disease.