Immature teratoma in the cerebral basal ganglia of an adult.

A 19-year-old male underwent an emergent operation for a massive brain tumor in the right cerebral basal ganglia. However, brain herniation had already developed and he subsequently died. Histological examination showed the tumor consisted of immature epithelial arrangements and glandular structures, considered as immature teratoma containing choriocarcinomatous components. Such an immature teratoma arising in the cerebral basal ganglia in an adult is very rare.