Posterior location of the facial nerve on vestibular schwannoma: Report of a rare case and a literature review.

Background: Posterior location of the facial nerve in relation to vestibular schwannoma (VS) is extremely rare.

Case description: An elderly man presented with the right cerebellopontine angle (CPA) syndrome. Magnetic resonance imaging showed the partly cystic and partly solid right CPA lesion extending to the internal auditory meatus. Seventh nerve monitoring showed the facial nerve on the posterior surface of the tumor. At surgery, the facial nerve was seen on the posterior surface of the tumor under the microscope. Partial excision of the tumor was done with preservation of the facial nerve both anatomically and electrophysiologically.

Conclusion: The posterior location of the facial nerve should be anticipated in all patients with VS. The surgical strategy must be altered appropriately to preserve the facial nerve.