Endoscopic resection of an anterior skull-base Schwannoma

Role of endoscopic surgery in the management of sinonasal and skull base schwannomas

BACKGROUND

The purpose of this study was to report our experience with the endoscopic management of sinonasal schwannomas, analyzing the advantages, limitations, and outcomes of the technique.

METHODS

A retrospective analysis was carried out on 11 patients treated endoscopically between 2000 and 2014 at a single institution.

RESULTS

Eight patients underwent an exclusive endoscopic endonasal approach, whereas, in 3 patients, an osteoplastic flap was combined because of massive or lateral frontal sinus involvement. The tumor extended into the orbit in 5 cases, and involved the skull base in 5 patients who required a concomitant endoscopic duraplasty. No evidence of disease was observed in 10 patients after a mean follow-up of 90.1 months (range, 14-189 months). One patient was alive with persistence of disease, although asymptomatic.

CONCLUSION

The endoscopic endonasal approach is a valid alternative for the vast majority of sinonasal schwannomas with minimal morbidity for the patient. © 2016 Wiley Periodicals, Inc. Head Neck 38: E2074-E2082, 2016.

Schwannomas of the sinonasal tract and anterior skull base: a systematic review of 94 cases

BACKGROUND

Schwannomas of the anterior skull base (ASB) and sinonasal tract are extremely rare. These lesions mimic other pathologies such as olfactory groove meningiomas, hemangiopericytomas, and esthesioneuroblastomas. Because of their low incidence, ASB and sinonasal tract schwannomas have not been well characterized. A systematic review of ASB and sinonasal tract schwannomas was conducted to further elucidate the presentation and surgical management of these lesions.

METHODS

A MEDLINE/PubMed search was performed, identifying 71 articles representing 94 cases of ASB and sinonasal schwannomas. Each case was analyzed for demographics, clinical presentation, anatomic location, radiographic features, and surgical treatment.

RESULTS

In 94 patients with ASB and sinonasal schwannomas, 44 (46.8%) were exclusively sinonasal, 30 cases (31.9%) were exclusively intracranial, 12 (12.8%) were primarily intracranial with extension into the paranasal sinuses, and 8 (8.5%) were primarily sinonasal with intracranial extension. Headaches and nasal obstruction were the most common presenting symptoms occurring in 30.9 and 29.8% of cases, respectively. Magnetic resonance imaging typically showed a hyperintense mass on T2-weighted imaging (70%) and hypointense (41%) on T1-weighted imaging. Most patients underwent surgical gross total resection via craniotomy, endoscopic endonasal approach, rhinotomy, or other sinonasal approaches. Recurrence occurred in three cases ranging from 4 months to 13 years. Postoperative complications included cerebral spinal fluid leakage, bacterial meningitis, epidural hematoma, and pneumocranium.

CONCLUSION

ASB and sinonasal schwannomas are rare lesions and should be considered in the differential diagnosis of ASB masses involving the cribriform plate with sinonasal extension. Gross total resection of these lesions should be considered the goal of operative management.

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.