Cellular Schwannoma of the Greater Superficial Petrosal Nerve Presenting with Abducens Nerve Palsy and Xerophthalmia: Case Report

ABSTRACT OBJECTIVE Cellular schwannomas (CS) are rare in the cranial space. This report is the first of a patient with a greater superficial petrosal nerve CS presenting with abducens nerve palsy and xerophthalmia. CLINICAL PRESENTATION A 16-year-old female patient presented with a 1-month history of diplopia. Neurological examination was normal except for the presence of right abducens nerve palsy. Schirmer's test revealed decreased tear secretion in the right eye. Computed tomography and magnetic resonance imaging showed a mass in the right petrous apex. It was thought that the schwannoma in our patient originated from the greater superficial petrosal nerve, based on the location of the tumor in addition to the absence of partial Horner's syndrome and a persistent decrease in tear secretion. INTERVENTION: The tumor was exposed with the use of a right subtemporal extradural approach and removed entirely. Pathological evaluation of the tumor revealed a CS. CONCLUSION The abducens nerve palsy improved completely in the follow-up period, but the decreased tear secretion did not resolve. CS is one of the subtypes of ordinary schwannomas and exhibits malignant features on microscopic examination, although it has a good clinical prognosis. No adjuvant treatment was applied because of the tumor's benign character. The greater superficial petrosal nerve schwannoma should be considered in the differential diagnosis of the abducens nerve palsy and petrous apex mass.