Ovarian steroid cell tumor, not otherwise specified: A rare case of postmenopausal vaginal bleeding

Ovarian steroid cell tumors (SCTs), not otherwise specified (NOS) are particularly rare ovarian tumors, which are composed of steroid-hormone secreting cells. The majority of patients with this tumor produce excessive quantities of testosterone and virilization is common. The current report presents a rare case of SCT in a 59-year-old female who presented with postmenopausal vaginal bleeding. The patient had experienced irregular vaginal bleeding for two months, 12 years after menopause. Transvaginal ultrasound and magnetic resonance imaging identified a solid adnexal mass and the pathological result of diagnostic curettage showed a proliferative endometrium. The patient's serum estrogen and testosterone levels were elevated (393.71 nmol/l and 22.28 nmol/l, respectively). The patient underwent an exploratory laparotomy, hysterectomy and bisalpingectomy. The neoplasm was well-circumscribed, solid, homogeneous and yellow in color. Microscopically, the tumor was predominantly composed of granular eosinophilic or vacuolated cytoplasm. Reinke's crystals, prominent nucleoli and Call-Exner bodies were not observed, and there was no mitotic figure. Immunohistochemistry demonstrated that the tumor cells were strongly positive for inhibin. The present rare case aims to expand the current knowledge of this type of ovarian tumor.