Unilateral Endoscopic Endonasal Surgery for Resection of an Olfactory Schwannoma of the Anterior Cranial Base in a Patient with Hereditary Hemorrhagic Telangiectasia

• Published in: World neurosurgery Vol. 89; pp. 729.e15 - 729.e20
• Main Authors: Pereira, Marcelo Charles, Peris-Celda, Maria, Qian, Jiang, Kenning, Tyler J, Pinheiro-Neto, Carlos D
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01-05-2016
• Subjects: Adult; Anterior skull base tumor; Brain Neoplasms - complications; Brain Neoplasms - diagnostic imaging; Brain Neoplasms - surgery; Endonasal approach to schwannoma; Endoscopic endonasal approach; Endoscopic skull base surgery; Female; Humans; Magnetic Resonance Imaging; Neurilemmoma - complications; Neurilemmoma - diagnostic imaging; Neurilemmoma - surgery; Neuroendoscopy - methods; Neurosurgery; Neurosurgical approach to schwannoma; Neurosurgical Procedures - methods; Olfactory Bulb - surgery; Olfactory Pathways - surgery; Olfactory schwannoma; S100 Proteins - metabolism; Telangiectasia, Hereditary Hemorrhagic - complications; Telangiectasia, Hereditary Hemorrhagic - diagnostic imaging; Telangiectasia, Hereditary Hemorrhagic - surgery; T1-weighted imaging; Olfactory schwannoma; MRI; SPA; T1WI; Anterior skull base tumor; Hereditary hemorrhagic telangiectasia; Endoscopic skull base surgery; ASB; Neurosurgical approach to schwannoma; Sphenopalatine artery; T2-weighted imaging; Magnetic resonance imaging; HHT; T2WI; Endonasal approach to schwannoma; Anterior skull base; Endoscopic endonasal approach
• ISSN: 1878-8750; 1878-8769
• DOI: 10.1016/j.wneu.2016.01.050

Background Olfactory schwannomas of the anterior cranial base (ACB) are rare tumors, and their association with hereditary hemorrhagic telangiectasia (HHT) has not previously been described. The majority of ACB schwannomas arise from the sinonasal tracts and may demonstrate intracranial extension. We report a case of an olfactory schwannoma-dense adherence to the basal frontal lobe. Complete tumor resection was performed through a unilateral extended endonasal endoscopic approach with preservation of the contralateral olfactory bulb. Anterior cranial base repair was achieved with the use of a mucoperichondrial vascularized pedicled nasoseptal flap. Clinical Presentation A 25-year-old woman with a history of migraines presented with unilateral epistaxis and progressive worsening of her headache symptoms. The patient had a history of HHT. Nasal endoscopy showed mild telangiectasias, but no clear evidence of a mass. A computerized tomographic scan showed a large left-sided expansile lesion in the left ethmoid region with expansion and remodeling of the anterior cranial base and medial left orbit. Magnetic resonance imaging with contrast showed the mass to be avidly enhancing. Angiography was performed and demonstrated a mild vascular blush. Conclusions We report a rare case of HTT and olfactory schwannoma completely resected with a unilateral extended endoscopic endonasal approach. Reconstruction was performed with the use of nasoseptal flap. This is the first reported single-stage fully endoscopic endonasal unilateral approach for resection of an olfactory schwannoma with preservation of the contralateral olfactory cleft. The patient's sense of smell and taste was maintained after surgery.