title: Unilateral Endoscopic Endonasal Surgery for Resection of an Olfactory Schwannoma of the Anterior Cranial Base in a Patient with Hereditary Hemorrhagic Telangiectasia.
abstract: 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.
  
  
  METHODS
  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.
authors.affiliation: Division of Otolaryngology/Head and Neck Surgery, Department of Surgery, Albany Medical Center, Albany, New York.
authors.forename: Marcelo Charles
authors.initials: MC
authors.lastname: Pereira
authors.affiliation: Department of Neurosurgery, Albany Medical Center, Albany, New York.
authors.forename: Maria
authors.initials: M
authors.lastname: Peris-Celda
authors.affiliation: Department of Pathology, Albany Medical Center, Albany, New York.
authors.forename: Jiang
authors.initials: J
authors.lastname: Qian
authors.affiliation: Department of Neurosurgery, Albany Medical Center, Albany, New York.
authors.forename: Tyler J
authors.initials: TJ
authors.lastname: Kenning
authors.affiliation: Division of Otolaryngology/Head and Neck Surgery, Department of Surgery, Albany Medical Center, Albany, New York. Electronic address: PinheiC@mail.amc.edu.
authors.forename: Carlos D
authors.initials: CD
authors.lastname: Pinheiro-Neto
mesh_terms: D000328:Adult; D001932:Brain Neoplasms / Q000150:complications / Q000000981:diagnostic imaging / Q000601:surgery*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D009442:Neurilemmoma / Q000150:complications / Q000000981:diagnostic imaging / Q000601:surgery*; D044583:Neuroendoscopy / Q000379:methods*; D019635:Neurosurgical Procedures / Q000379:methods*; D009830:Olfactory Bulb / Q000601:surgery*; D009833:Olfactory Pathways / Q000601:surgery; D009418:S100 Proteins / Q000378:metabolism; D013683:Telangiectasia, Hereditary Hemorrhagic / Q000150:complications / Q000000981:diagnostic imaging / Q000601:surgery*
chemical_list: D009418:S100 Proteins
keywords: Anterior skull base tumor; Endonasal approach to schwannoma; Endoscopic endonasal approach; Endoscopic skull base surgery; Neurosurgical approach to schwannoma; Olfactory schwannoma