A Rare Case of Schwannoma Arising from the Dura Mater of the Petrosal Surface in the Posterior Cranial Fossa.

Abstract

An intracranial schwannoma originating in the dura mater is extremely rare. Herein, we report a case of schwannoma arising from the dura mater of the petrosal surface in the posterior cranial fossa. A 48-year-old man presented with slight gait disturbance and papilledema. Magnetic resonance imaging showed a T1- and T2-weighted mixed-intensity extra-axial tumor, approximately 4 cm in the maximum diameter with multiple small cysts, in the left posterior cranial fossa. The tumor was heterogeneously enhanced with gadolinium. Operative findings via a lateral suboccipital approach revealed that the tumor did not adhere to any cranial nerves but to the dura mater of the petrosal surface. The tumor was completely excised without any neurologic deficits, and the histologic diagnosis was schwannoma. The operative and postoperative findings suggested that the schwannoma originated in the meningeal branch of the lower cranial nerves or upper cervical nerves in the dura mater of the petrosal surface in the posterior cranial fossa.