Germ cell neoplasms arising in gonadoblastomas.

Gonadoblastomas have a propensity to give rise to germ cell neoplasms. This study analyzes the clinicopathologic findings in six phenotypic females with features of 46,XY pure gonadal dysgenesis who developed germinomas and other germ cell tumors in gonadoblastomas. All stages in the evolution of germinoma from the germ cells of gonadoblastoma were observed, including in situ, incipient, microinvasive, and metastatic varieties. Admixtures with teratoma and endodermal sinus tumor occurred in two patients. Germ cell tumors which originate in gonadoblastomas appear to have the same clinical behavior and response to therapy as those that arise de novo in the ovary, testis or extragonadal sites. Although it is debatable whether gonadoblastomas are true neoplasms or blastomatoid dysgenetic malformations, their potential for giving rise to fully malignant germ cell neoplasms must be recognized.