Pure nongestational choriocarcinoma of the ovary. Report of a case.

The authors report a case of pure nongestational choriocarcinoma of the ovary (NGCO) in a prepubertal female patient and emphasize the electron microscopic and immunohistochemical findings. Pure NGCO accounts for 0.6% or less of all ovarian neoplasms. Distinction from gestational choriocarcinoma of the ovary (GCO) is important because of the worse prognosis of NGCO. No distinctive ultrastructural or immunohistochemical differences were found between NGCO and GCO. Cytogenetic studies may be indicated in future cases to investigate potential reasons for the difference in prognosis.