Supratentorial extraventricular ependymoma presenting calvarial erosion: A report of 3 cases.

Calvarial erosion is an infrequent manifestation associated with oligodendrogliomas, astrocytomas, dysembryoplastic neuroepithelial tumors, astroblastomas, glioblastomas, and meningiomas. Anaplastic ependymoma (AE), a rare malignant form of ependymoma, commonly results in poor prognosis. During the last 12 years, six patients were diagnosed with supratentorial ependymomas. All of them were AEs with extraventricular location identified in the right parietal, left parietal, and left frontal lobes, respectively. Three of them, 7-, 15, and 17-year-old male patients, presented focal calvarial erosion with smooth contour. Calvarial erosion may be a diagnostic hallmark of supratentorial AEs.