Supratentorial pure cortical ependymoma.

Abstract Ependymoma usually occurs in the lateral or the fourth ventricle. Supratentorial extraventricular ependymoma is relatively rare. However, extraventricular ependymoma located at the cerebral cortex is extremely rare. We treated a 20-year-old woman who presented with generalized seizures. Cranial CT scan revealed a calcified mass in the left precentral gyrus. MRI confirmed an extraventricular, 12-mm-diameter intracortical mass. After gadolinium injection, tumor enhancement was mild and heterogeneous. The tumor was totally resected without neurological deterioration. Histological features were consistent with ependymoma, forming perivascular pseudorosettes without anaplastic figures. Immunohistochemistry showed positive staining for glial fibrillary acidic protein, S-100, and epithelial membrane antigen. A diagnosis of ependymoma of World Health Organization grade II was made. The patient has not had a seizure since the operation. There has been no clinical or radiologic evidence of recurrence during a 16-month postoperative follow-up.