Giant granulosa cell tumor of the ovary with continuous uterine bleeding after nine-year period of amenorrhea in a perimenopausal woman

The signs of granulosa cell tumors（GCTs）arising from the ovary depend on the types of hormones produced by the tumor. Estrogens cause continuous uterine bleeding, whereas inhibins are responsible for amenorrhea. We describe an unusual case of GCT in which the tumor-related manifestations changed over 9 years, from initial secondary amenorrhea to continuous uterine bleeding. Magnetic resonance imaging revealed a suspected ovarian tumor, and bilateral adnexectomy was performed. The preoperative serum hormone levels（luteinizing hormone, 0.5 mIU/mL; follicle-stimulating hormone, ＜0.05 mIU/mL; estradiol, 279 pg/mL）returned to the normal menopausal range after tumor resection（11.43 mIU/ mL, 23.80 mIU/mL, and ＜10 pg/mL, respectively）. The preoperative serum inhibin B levels were high, and the tumor tissue was diffusely immunostained with inhibin α. The woman had never experienced estrogen-deficiency symptoms. Therefore, we believe that the tumor produced inhibins initially, which led to hypogonadotropic amenorrhea that manifested as apparent early menopause, and estrogens subsequently, which caused continuous uterine bleeding over the years.