Staged and Combined Approach for Resection of Giant Posterior Fossa and Temporal Bone Schwannoma

Vestibular schwannomas have an estimated incidence of 1.09/100,000 people, representing 6%L10% of intracranial tumors.(1-4) Rarer giant vestibular schwannomas are defined by an extrameatal diameter of >= 4 cm and can be difficult to treat because of displacement and compression of local neuro-vasculature and the potential for multicompartment involvement. A 20-year-old woman with history of presumed right-sided Bell palsy and unexplained hearing loss was found to have a 9 X 8 X 6-cm giant posterior fossa schwannoma on syncopal workup (Video 1). It extended from the Meckel cave anterosuperiorly to below the skull base through the jugular foramen, filling the petrous apex and compressing the cerebellum, pons, and midbrain. She had ipsilateral facial weakness (House-Brackmann 3/5), V2 numbness, tongue deviation, vocal fold paresis, and hearing loss. A combined petrosal (transotic, extended middle fossa) and retrosigmoid approach was performed through a curvilineal incision that provided access to the middle fossa, petrous apex, and posterior fossa down to the jugular foramen and included a trajectory along the long axis of the tumor (retrosigmoid). Although we hypothesize this was a vestibular schwannoma, it was difficult to ascertain the exact origin of the tumor because of its massive size. Surgery was performed in 2 stages because of the large tumor size and to limit blood loss. A gross total resection was achieved. Closure included an autologous fat and synthetic cranioplasty. The patient was neurologically stable postoperatively, except for transient swallowing difficulty due to partial cranial nerve IX/X palsies. This case illustrates important considerations when combining surgical approaches for complex tumors involving multiple intracranial compartments.