Hilus cell tumour of the ovary in a virilized, premenopausal woman. Case report and review of hyperandrogenism of ovarian origin.

A 35 year-old woman presented with virilization and was found to have elevated serum testosterone levels. Investigation revealed an 11 mm hilus cell tumour in the left ovary. After unilateral oophorectomy, serum testosterone levels rapidly returned to normal levels. The various ovarian tumours and conditions causing virilization are described and a clinical approach to the investigation of virilization is outlined.