Nasoethmoid Ancient Schwannoma with Bilateral Intracranial Extension: A Case Report with Review of the Literature.

INTRODUCTION

Nasoethmoid schwannomas are rare benign tumors of the nasal cavity and paranasal sinuses that arise from local peripheral nerve sheaths. Up to 45% of all schwannomas develop in the head and neck region; however, fewer than 50 cases have been described in the nasoethmoid area in the medical literature. This case underscores the importance of including schwannoma in the differential diagnosis of nasoethmoidal masses with skull-base involvement.

CASE REPORT: A 60-year-old female presented with diminished sensitivity to smell for 12 months, swelling near left medial canthus and headache for the past 10 months. Nasal endoscopy revealed a smooth encapsulated mass in the anterior roof of nasal cavity between middle turbinate and septum bilaterally. CT and MRI revealed a smooth mass in the roof of nasal cavity having intracranial extra-axial extension. Biopsy displayed features of schwannoma. Patient underwent excision of tumor via combined approach of endoscopy and bifrontal craniotomy. Post-operative histopathology was consistent with features of schwannoma.

CONCLUSION

Nasoethmoidal schwannoma is a benign neoplasm that infrequently exhibits intracranial extension. To date, there have been 17 documented cases in the literature, and this report presents the 18th reported case overall and 6th bilateral case. Because radiographic results are ambiguous, a histological investigation is required for a precise diagnosis. Bifrontal craniotomy combined with endoscopic transnasal excision is the preferred surgical treatment for tumors that extend into the anterior cranial fossa. Long-term clinical follow-up is critical for detecting future recurrences.