Endocrine function of granulosa cell tumors in vivo

Two patients with granulosa cell tumors of the ovary, endometrial hyperplasia, elevated serum estradiol (E2) concentrations and depressed FSH levels were studied preoperatively using intravenous administration of FSH, LH and gonadotropin-releasing hormone. In patient 1, serum E2 increased from a baseline of 72.7 to 116.8 pg/ml 60 min after hCG stimulation, with a peak level of 571.4 pg/ml 96 h after hCG administration; there was a rapid postoperative decline to 16 pg/ml. Ovarian venous E2 on the tumor side was 6,979 pg/ml. In patient 2, E2 increased from a baseline of 91 to 449 pg/ml at 20 h after FSH administration. Intraoperative ovarian venous E2 was 9,788 pg/ml. Inhibin, which was elevated in patient 1 prior to stimulation (736 fmol/ml), peaked 96 h after hCG administration. Ovarian venous inhibin concentration in patient 1 was 2,911 fmol/ml. The baseline inhibin concentration in patient 2 was not elevated (249 fmol/ml), but there was an elevation of inhibin in response to FSH administration (757 fmol/ml), but no response to hCG. Ovarian inhibin concentration was not different between the tumor and contralateral sides in patient 2. Both granulosa cell tumors were responsive to exogenous gonadotropin stimulation. Although only one tumor made significant baseline levels of inhibin, the production of inhibin by both tumors was apparently stimulated by FSH.