Dysgerminoma with syncytiotrophoblastic giant cells arising from 46,XX pure gonadal dysgenesis

Dysgerminoma with syncytiotrophblastic giant cells is a rare ovarian tumor. Only ten cases of this tumor have been reported, and all tumors developed in normal ovaries. This report presents a case of dysgerminoma with syncytiotrophoblastic giant cells arising in a patient with 46,XX pure gonadal dysgenesis.

An 18-year-old phenotypic female of normal height without somatic anomalies with nonfunctional ovaries underwent a bilateral gonadectomy for a right ovarian tumor and left streak gonad. The tumor revealed a dysgerminoma containing scattered syncytiotrophoblastic giant cells. Her serum hCG was elevated, and hCG was demonstrated within syncytiotrophoblastic giant cells immunohistochemically. The clinical diagnosis was stage Ia dysgerminoma with syncytiotrophoblastic giant cells. Her karyotype was 46,XX and the sex-determining region Y gene was not detected in tumor DNA by polymerase chain reaction analysis.

This rare gonadal tumor may arise from dysgenetic gonads in addition to gonadoblastoma and pure dysgerminoma. It is an example of tumorgenesis in pure gonadal dysgenesis with no identifiable Y chromosome component.