title: Intracanalicular facial nerve schwannoma.
abstract: OBJECTIVE
  To investigate the capability of preoperative evaluations in predicting the precise anatomic origin of intracanalicular tumors.
  
  
  METHODS
  We conducted a retrospective case review.
  
  
  METHODS
  Tertiary referral center.
  
  
  METHODS
  A total of 11 patients (8 men and 3 women, 26-70 years old) with intracanalicular tumors who were treated surgically were included.
  
  
  METHODS
  Pure-tone average, auditory brainstem response, caloric test, and temporal magnetic resonance imaging were done in all 11 patients. Electroneuronography has only been performed since 2003, and only 3 patients were evaluated.
  
  
  METHODS
  Preoperative symptoms, pure-tone average, auditory brainstem response, caloric test, electroneuronography, and magnetic resonance imaging were compared between patients with facial nerve schwannomas and patients with vestibular schwannomas.
  
  
  RESULTS
  Postoperatively, facial nerve schwannomas were diagnosed pathologically in 2 (18%) of 11 patients. There were not any clues suggesting facial nerve schwannoma in preoperative evaluations.
  
  
  CONCLUSIONS
  A facial nerve schwannoma may be misdiagnosed as a vestibular schwannoma, especially when the tumor is confined to the internal auditory canal. There are no useful preoperative evaluation tools in predicting the precise nerve origin of intracanalicular tumors. These emphasize the need to fully inform the patient preoperatively.
authors.affiliation: Department of Otorhinolaryngology, Yonsei University, College of Medicine, Seoul, South Korea.
authors.forename: Hun Yi
authors.initials: HY
authors.lastname: Park
authors.forename: Sung Huhn
authors.initials: SH
authors.lastname: Kim
authors.forename: Eun Jin
authors.initials: EJ
authors.lastname: Son
authors.forename: Ho-Ki
authors.initials: HK
authors.lastname: Lee
authors.forename: Won-Sang
authors.initials: WS
authors.lastname: Lee
mesh_terms: D000328:Adult; D000368:Aged; D001301:Audiometry, Pure-Tone; D003390:Cranial Nerve Neoplasms / Q000473:pathology* / Q000601:surgery; D003937:Diagnosis, Differential; D007758:Ear, Inner; D016057:Evoked Potentials, Auditory, Brain Stem / Q000502:physiology; D005154:Facial Nerve / Q000473:pathology* / Q000601:surgery; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009442:Neurilemmoma / Q000473:pathology* / Q000601:surgery; D009464:Neuroma, Acoustic / Q000473:pathology; D013506:Otologic Surgical Procedures; D012189:Retrospective Studies