title: Hypoglossal neurinoma extending intra- and extracranially: case report.
abstract: BACKGROUND
  Hypoglossal neurinoma is very rare; our case is the 46th case.
  
  
  METHODS
  We report a 59-year-old woman with hypoglossal neurinoma. Her equilibrium state was disturbed due to vestibular dysfunction and she exhibited right hypoglossal palsy with glossal hemiatrophy. Computed tomography (CT) revealed a large bony erosion of the right hypoglossal canal. Magnetic resonance imaging (MRI) revealed intra- and extracranial tumor extension. There was an intracranial mass attached to the enlarged hypoglossal vertebral and posterior inferior cerebellar artery medially. The extracranial part of the mass extended along the course of the hypoglossal nerve through the enlarged hypoglossal canal. The intracranial part of the tumor was totally removed via the transcondylar approach. The diameter of the origin of the posterior interior cerebellar artery was narrow before tumor removal; it increased after surgery due to decompression. A histological diagnosis of neurilemoma was made. Her symptoms due to vestibular dysfunction disappeared postoperatively.
  
  
  CONCLUSIONS
  Our patient's difficulty with balance was thought to be an ischemic symptom due to circulation disturbance of the posterior inferior cerebellar artery. It disappeared after tumor removal. Surgery may be necessary later if further growth of the extracranial part of the neurinoma becomes evident.
authors.affiliation: Department of Neurosurgery, Toyonaka Municipal Hospital, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Sato
authors.forename: N
authors.initials: N
authors.lastname: Kanai
authors.forename: Y
authors.initials: Y
authors.lastname: Fukushima
authors.forename: S
authors.initials: S
authors.lastname: Matsumoto
authors.forename: C
authors.initials: C
authors.lastname: Tatsumi
authors.forename: K
authors.initials: K
authors.lastname: Kitamura
authors.forename: M
authors.initials: M
authors.lastname: Ozaki
authors.forename: T
authors.initials: T
authors.lastname: Hayakawa
mesh_terms: D001932:Brain Neoplasms; D003390:Cranial Nerve Neoplasms; D005260:Female; D006801:Humans; D007002:Hypoglossal Nerve; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D009442:Neurilemmoma; D014057:Tomography, X-Ray Computed