Seminoma in 46, XY Gonadal Dysgenesis: Rare Presentation and Review of the Literature.

Swyer syndrome is a rare congenital condition that serves as a risk factor for developing germ cell tumors. The condition belongs to the group of 46, XY disorders of sexual development, is characterized by complete gonadal dysgenesis (CGD) and is mostly manifested as delayed puberty and primary amenorrhea during adolescence. Individuals with Swyer syndrome are known to be phenotypically female with normal internal and external female genitalia at birth. 46, XY GD involves a high risk of gonadoblastoma development with malignant potential such that the onset is greatest at or after the event of puberty. This report of a 12-year-old phenotypic female with 46, XY GD, who developed an advanced metastatic seminoma, highlights the rarity of the development of a seminoma in the context of 46, XY CGD.