Hearing improvement after conservative approach for large posterior fossa meningioma.

Hearing preservation during the posterior fossa surgery depends on many factors, including tumor size and site of origin. In many cases, regardless of the presumed tumor origin, the severity of the pure-tone loss or decline in speech discrimination on preoperative testing prompts the surgeon to choose a surgical approach (translabyrinthine or transcochlear) that negates the chance for postoperative functional hearing in the involved ear. We describe a 41-year-old woman with unilateral severe sensorineural hearing loss who experienced a remarkable recovery of hearing after combined retrolabyrinthine and retrosigmoid removal of a 4 cm petrous ridge meningioma using intraoperative cochlear monitoring. Despite the tumor size, early intraoperative loss of wave I and proximity of the tumor to the porus, complete tumor removal was accomplished with preservation of the cochleovestibular bundle. Three weeks postoperatively, the patient noted marked subjective improvement and speech audiometry demonstrated an improvement in word recognition, from 0% to 86%. This improvement has remained 1 year postoperatively, with no evidence of persistent tumor on repeat MRI scan. The case report illustrates the possibility of not just hearing preservation but improvement after removal of even large posterior fossa meningiomas that do not directly invade the cochlear nerve itself.