Primary intracranial choriocarcinoma: a case report.

A 10-year-old girl had a primary choriocarcinoma of the posterior third ventricle. Craniotomy a few hours before death did not yield any tumor tissue. At autopsy, an extensively hemorrhagic tumor abutted the pineal gland. Immunostains were positive for beta-human chorionic gonadotropin (beta-HCG) but were negative for alpha-fetoprotein and carcinoembryonic antigen. The presence of beta-HCG in serum or cerebrospinal fluid may be used as a diagnostic marker and monitor of therapy. HCG is, however, not a unique marker for trophoblastic neoplasms, as a significant number of intracranial germinomas contain cells that are beta-HCG positive. Because of the rarity of primary extragenital choriocarcinomas and the much more common occurrence of metastases of genital choriocarcinomas, it is doubtful whether any investigation less than detailed autopsy can prove the extragenital origin of the tumor.