Schwannoma of the 6th nerve: case report and review of the literature

Abstract

Schwannomas of the 6th nerve are extremely rare.Only 22 cases of intracranial schwannomas of the 6th cranial nerve pathologically confirmed have been reported. Here, we report a case of a 14-year-old girl who presented with isolated progressive 6th nerve palsy. A cisternal type of schwannomawas found from neuro-imaging. Subtotal removal of the tumor was performed by a routine left subtemporal craniotomy with an petrosectomy. The attachment to the 6th nerve was found. After surgery, the patient’s 6th nerve palsy remained. Histological images revealed a cellular schwannoma. Then the classification, clinical presentation, diagnosis, operation, stereotactic radiosurgery are reviewed. The location and the attachment to the 6th nerve is the key for diagnosis. Most cases are treated surgically. It looks like it is not easy to completely remove for CA type because of invasion of the cavernous sinus or firm adherence to the nerves. The 6th nerve function seldom completely recovered postoperatively. The direction of further research is to improve the diagnosis and therapy to have better nerve recovery.