Epidermoid Cyst with Torcular Herophili Obstruction and Unusual Venous Drainage.

Abstract

An epidermoid cyst arising from diploic space in the skull can cause an intracranial mass effect with compression of the underlying venous sinuses. A 66-year-old woman came to us with a persistent headache and unsteadiness. Computed tomography demonstrated an occipital bone cystic lesion with an intracranial mass effect overlying the torcular herophili, with high-intensity findings in diffusion-weighted magnetic resonance imaging. Cerebral angiogram demonstrated obstruction of the torcular herophili with development of diploic venous drainage. The patient underwent removal of the lesion and a cranioplasty procedure. The diagnosis was torcular epidermoid cyst. The postoperative course was uneventful, and the symptoms were resolved. Development of diploic venous drainage contributed to avoidance of critical intracranial hypertension during slow growth of a torcular epidermoid cyst.