Norethindrone inhibition of testosterone secretion by an ovarian Sertoli-Leydig cell tumor.

A woman with severe hyperandrogenemia and virilization was found to have a fall in serum testosterone (T) concentration while taking an oral contraceptive containing norethindrone (500 vs. 164 ng/dL). Subsequent surgical exploration revealed an ovarian Sertoli-Leydig cell tumor. In vitro, the tumor secreted T (mean, 1.88 ng/mg X 4 h). hCG did not stimulate T secretion. In addition, norethindrone inhibited T secretion (0.33 ng/mg X 4 h). We conclude that norethindrone directly suppressed T production by the Sertoli-Leydig cell tumor.