A stromal Leydig cell tumor of the ovary occurring in a pregnant 15-year-old girl. Ultrastructural findings.

The first case of stromal Leydig cell tumor of the ovary occurring during pregnancy is reported. A 15-year-old girl presented in labor at 36.5 weeks of gestation. The tumor mass was obstructing labor and the patient had to be delivered by cesarean section. Unique features of this case included the young age of the patient, the large size of the tumor, and the associated pregnancy. The tumor was encapsulated and showed the typical histologic and ultrastructural features of ovarian stromal Leydig cell tumor. The literature is reviewed, and the differential diagnosis is discussed.