[Pure gonadal dysgenesis with 46 XY karyotyping (Swyer's syndrome) with gonadoblastoma, dysgerminoma and embryonal carcinoma].

We report the clinical and pathologic findings in a 22-year-old woman with XY gonadal dysgenesis (Swyer's syndrome), who had bilateral gonadoblastoma associated on the right side with a dysgerminoma and an embryonal carcinoma. Swyer's syndrome is a distinct type of pure gonadal dysgenesis characterized by a 46 XY karyotype. It shows an abnormality in testicular differentiation. The patients are phenotypic females without stigmas of Turner syndrome. They have also elevated gonadotropins and hypoplastic gonads without germ-cells. The tumor that usually develops in Swyer's syndrome is gonadoblastoma. This tumor arises on dysgenesic gonads with a Y chromosome. Although gonadoblastoma is considered benign, the risk of malignant germ cell development is high. This means that these dysgenesic gonads should be removed surgically as soon as Swyer's syndrome is established.