The tanycytic ependymoma of the lateral ventricle: case report.

The tanycytic ependymoma is an extremely rare, primitive neuroectodermal tumor, arising from the ependymoglial cells or tanycytes. Such cells are generally seen in the primitive nervous system instead of the mature ependymal cells. The tanycytic ependymoma described in this report was found in a 42-year-old man. Histological analysis strongly suggested that this tumor originated from a primitive progenitor cell, the ependymoglia or the tanycyte in the lateral ventricle.