Microsurgical excision of a pontomedullary epidermoid cyst with prepontine extension: case report.

We report the case of a patient with a pontomedullary epidermoid cyst extending into the prepontine cistern. The patient presented with a progressive VIth nerve palsy, ataxia, and headache. Magnetic resonance imaging demonstrated a well-defined pontomedullary tumor with a high fat content. We excised the lesion using a microsurgical approach through the floor of the fourth ventricle. Postoperative magnetic resonance imaging confirmed the removal of both intra- and extra-axial components. We discuss the anatomic configuration, radiological appearances, and management of this unusual pathological finding.