title: Neurocytoma of the VIIIth cranial nerve: case report.
abstract: OBJECTIVE
  Neurocytomas are uncommon tumors of the CNS. To date, none have been described in association with a cranial nerve. We described the clinicopathological features of an example arising in the cochlear-vestibular portion of the VIIIth nerve with extension into the cerebellopontine angle.
  
  
  METHODS
  The patient, a 42-year-old female, presented approximately 6 months ago with several episodes of worsening dizziness. On magnetic resonance imaging studies, a 2-cm enhancing lesion occupying the left internal auditory canal and protruding into the cerebellopontine angle cistern was detected with signal characteristics suggestive of vestibular neuroma.
  
  
  METHODS
  At surgery, the tumor was seen to originate from the cochlear-vestibular nerve bundle lying within the internal auditory canal, extended laterally to the level of the fundus and 4 mm medially into the cerebellopontine angle. No dural attachment was noted. With use of sharp dissection and bipolar cautery, portions of the tumor within the auditory canal were debulked.
  
  
  CONCLUSIONS
  A unique example of a neurocytoma in association with a cranial nerve is documented. Possible explanations for the occurrence are explored. The topography of neurocytomas continues to expand.
authors.affiliation: Department of Pathology and Laboratory Medicine, Mayo Clinic, Rochester, Minnesota 55905, USA.
authors.forename: Onder
authors.initials: O
authors.lastname: Onguru
authors.forename: Ozlem
authors.initials: O
authors.lastname: Kurtkaya-Yapicier
authors.forename: Bernd W
authors.initials: BW
authors.lastname: Scheithauer
authors.forename: Patrick
authors.initials: P
authors.lastname: Luetmer
authors.forename: Peter C
authors.initials: PC
authors.lastname: Burger
authors.forename: Sherrie J
authors.initials: SJ
authors.lastname: Mann
authors.forename: Steven A
authors.initials: SA
authors.lastname: Harvey
mesh_terms: D000328:Adult; D003390:Cranial Nerve Neoplasms / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods; D018306:Neurocytoma / Q000601:surgery*; D009493:Neurosurgery; D016708:Synaptophysin / Q000378:metabolism; D014057:Tomography, X-Ray Computed; D000159:Vestibulocochlear Nerve / Q000473:pathology* / Q000601:surgery
chemical_list: D016708:Synaptophysin