Dermoid cysts are rare congenital intracranial
tumors. Among these
tumors, extradural localization is extremely rare. We report a patient with an extradural
dermoid cyst of the right parasellar region, causing right visual disturbance. Computed tomography revealed a hypodense mass lesion with rimlike calcification at the right parasellar region, accompanying marked erosion of the adjacent skull base. The
tumor appeared as a heterogeneous intensity on magnetic resonance imaging and was surrounded by thin
gadolinium enhancement without inner enhancement. The right optic nerve was compressed by the
tumor. Surgical resection was successfully performed using a right frontotemporal extradural approach. The entire
tumor was completely resided extradurally and was enclosed by saclike, stretched dura mater and extended deeply into the skull base. Histopathologic findings were consistent with the features of
dermoid cyst. The postoperative course was uneventful, and the visual disturbance improved. Neuroradiological features, strategies for surgical treatment, and mechanisms responsible for preoperative symptoms are discussed.