The Masquerading, Masculinizing Tumor: A Case Report and Review of the Literature.

Androgen-producing tumors in women are rare neoplasms that can cause secondary virilizing characteristics. Of patients presenting with symptoms of hyperandrogenism, these tumors are found in ∼0.2% of cases. Androgen-producing tumors can arise from the ovary or the adrenal gland. Those arising from the ovary are rare, accounting for <5% of all ovarian tumors. This case presents a hilar Leydig cell tumor of the ovary, which resulted in secondary virilization of a 45-year-old female 2 months after cessation of combined oral contraceptives (COC). Laboratory findings showed markedly elevated total and free testosterone concentrations with normal dehydroepiandrosterone sulfate, however neither pelvic ultrasound nor magnetic resonance imaging demonstrated any masses. Venous sampling under fluoroscopy revealed supraphysiologic testosterone concentrations from the right ovarian vein suggesting the source. The patient underwent bilateral salpingo-oophorectomy revealing a 1.3 cm hilar cell tumor of the right ovary. This article reviews the clinical features, diagnosis, and treatment of hilar Leydig cell tumors and describes the long-term complications of supraphysiologic testosterone levels. As the tumor presented after cessation of COC, we also review the mechanisms by which COC might suppress supraphysiologic androgen levels and mask the secondary virilizing effects of androgen-producing tumors.