Endoscopic endonasal resection of sinonasal and anterior skull base schwannomas.

Sinonasal and anterior skull base (ASB) schwannomas are rare entities. The majority of these lesions are found within the sinonasal tract, although some have intracranial extension via invasion of the ASB. Often, these tumors can be confused for other entities, especially olfactory groove meningiomas and esthesioneuroblastomas in the olfactory groove region, and juvenile nasopharyngeal angiofibromas in the infratemporal fossa. We present a single institutional series of four patients with sinonasal and ASB schwannomas that were resected purely via an endoscopic endonasal approach. A retrospective chart review was performed to identify individuals with sinonasal and/or ASB schwannomas. Demographic data, presenting symptoms, imaging, treatment, and follow-up were recorded. Two male and two female patients were included in this study. The average age was 53.5 years (range, 21 to 71). The most common presenting symptoms were facial pain and hyposmia. All tumors were treated with endoscopic endonasal resection. One patient had intradural intracranial extension and required an extended endoscopic endonasal transcribriform approach with ASB resection, while another case involving the infratemporal fossa was treated with an extended endoscopic endonasal transpterygoid approach to this region. There were no major complications at an average follow-up of 9 months (range, 0 to 16). Sinonasal and ASB schwannomas are rare entities, with often nondescript symptoms and can often mimic other types of skull base tumors. Total resection via a purely endoscopic endonasal approach can be considered for these rare neoplasms.