Ovarian steroid cell tumor, not otherwise specified, producing testosterone

Steroid cell tumor, not otherwise specified, is a rare type of ovarian sex cord-stromal tumor with malignant potential. Some of these tumors produce testosterone. We describe a case of steroid cell tumor of the ovary associated with virilization. A 23-year-old nulliparous woman was found to have an ovarian tumor when she visited her primary doctor for virilization and oligomenorrhea. Magnetic resonance imaging revealed a solid left ovarian tumor 40 mm in size. Her laboratory data revealed elevated testosterone with normal levels of gonadotropins, estradiol, dehydroepiandrosterone sulfate and cortisol. She underwent left adnexectomy. On histopathologic and immunohistochemical analyses, the tumor was diagnosed as steroid cell tumor, not otherwise specified, without malignant behavior. After removal of the tumor, serum testosterone level decreased, and there have been no signs of recurrence.