An unusual case of intraventricular gliosarcoma

Gliosarcoma is an uncommon variant of glioblastoma characterized by a biphasic pattern of glial and mesenchymal differentiation in the tumor. These tumors occur mostly in the cerebral hemispheres. Intraventricular location is extremely rare. Extensive review of literature revealed only two cases of intraventricular gliosarcoma. The first case arose by malignant transformation of a preexisting ependymoma. The second case was a gliosarcoma involving the frontal lobe with extension into the lateral ventricle. We report a case of an exclusively lateral ventricular tumor probably arising from the interventricular septum and blocking the CSF pathway. To the best of our knowledge, this is the first reported case of an exclusively intraventricular gliosarcoma.