EFO_1001197 (subependymal glioma) is rare, slow-growing, benign intraventricular tumors, often asymptomatic and discovered incidentally. The tumors are classified histologically as ependymomas and demonstrate a proliferation of subependymal fibrillary astrocytes among the ependymal tumor cells. (From Clin Neurol Neurosurg 1997 Feb;99(1):17-22). Also known as: Glioma, Subependymal, Subependymal astrocytoma, Subependymal astrocytoma NOS, WHO grade I Ependymal tumor, mixed subependymoma-ependymoma.