Fibrocystic breast disease: the significance of beta-human chorionic gonadotropin and other polypeptides in breast cyst fluid.

Breast cyst fluids from 118 women, aged 29 to 69 years, were analyzed by radioimmunoassays for beta-human chorionic gonadotropin (beta-hCG), luteinizing hormone (LH), follicle-stimulating hormone (FSH), prolactin (PRL), and thyroid-stimulating hormone (TSH). Blood was drawn at the same time in many cases to compare hormonal levels in serum with those in the breast cyst fluids (BCF). The levels of beta-hCG in BCF were relatively high, with a mean (+/- standard error of the mean [SEM]) of 58.9 +/- 16.8 mIU/ml; serum levels of beta-hCG were negligible. LH and TSH also were elevated in BCF compared with serum levels, exhibiting mean values (+/- SEM) of 26.7 +/- 4.3 mIU/ml and 6.4 +/- 0.44 muIU/ml, respectively. The levels of FSH and PRL in BCF were equivalent to the levels in the serum. The presence of biologically active hCG was suggested in several BCF samples using the rat ovarian hyperemia test. Samples of BCF were assessed for the capacity to stimulate Leydig cell testosterone production in vitro in the presence or absence of an anti-hLH antiserum. Testosterone production was significantly (P less than 0.05) enhanced, even in the presence of the antiserum. These data suggest that BCF contains biologically active hCG.