A 2-Staged Approach for Resection of Giant Dumbbell Shaped Facial Nerve Schwannoma With Facial Nerve Preservation

BACKGROUND AND IMPORTANCE: Facial nerve schwannoma (FNS) is a rare, nerve sheath tumor that presents unique surgical challenges, particularly large tumors involving multiple anatomic compartments. Preservation of facial nerve function while ensuring adequate tumor resection remains the primary goal in management. CLINICAL PRESENTATION: The patient was a 37-year-old man with a 4-year history of left-sided hearing loss and worsening balance with intact facial nerve function. MRI and computed tomography demonstrated a 7.5-cm dumbbell lesion occupying the posterior and middle fossa consistent with a FNS. We describe a 2-staged approach for resecting a giant FNS: stage 1 used a retrosigmoid craniotomy for posterior fossa tumor resection, and stage 2 used a middle fossa approach. Near total tumor resection was achieved while preserving the facial nerve function at House-Brackman 1 grade. CONCLUSION: Giant FNS with significant mass effect warrant surgical resection. Facial nerve preservation is feasible depending on the location of functional nerve fascicles relative to the tumor. Direct electrophysiologic nerve stimulation at lower threshold is necessary to identify such fascicles.