title: Extradural neuromas at the petrous apex: report of two cases.
abstract: OBJECTIVE
  Two rare cases of middle cranial fossa neuroma located in the epidural space at the petrous apex are reported.
  
  
  METHODS
  Two women, aged 58 and 49 years, were admitted to our hospital with diagnoses of cavernous sinus tumor. Analysis of preoperative computed tomography scans showed bone erosion of the petrous apex, and magnetic resonance imaging demonstrated the presence of an extradural mass located along the course of the petrous internal carotid artery in both patients.
  
  
  METHODS
  The tumor was completely removed in one patient and partially removed in the other by use of the epidural middle cranial fossa transpetrosal approach. In both patients, histological examination of tumor specimens revealed neuroma.
  
  
  CONCLUSIONS
  Because surgical exploration revealed that these epidural tumors adhered tightly to the internal carotid artery, and because they had no relationship to the trigeminal nerve, facial nerve, or proximal greater superficial petrosal nerve, in our opinion, these tumors originated from the distal portion of the greater superficial petrosal nerve or the deep petrosal nerve. These neuromas were mainly found in a site under the cavernous sinus at the petrous apex, a location not previously reported.
authors.affiliation: Department of Neurosurgery, Akita University School of Medicine, 1-1-1 Hondo, Akita 010-8543, Japan. kinouchi@nsg.med.akita-u.ac.jp
authors.forename: H
authors.initials: H
authors.lastname: Kinouchi
authors.forename: S
authors.initials: S
authors.lastname: Mikawa
authors.forename: A
authors.initials: A
authors.lastname: Suzuki
authors.forename: T
authors.initials: T
authors.lastname: Sasajima
authors.forename: N
authors.initials: N
authors.lastname: Tomura
authors.forename: K
authors.initials: K
authors.lastname: Mizoi
mesh_terms: D002343:Carotid Artery, Internal / Q000473:pathology / Q000601:surgery; D002426:Cavernous Sinus / Q000473:pathology / Q000601:surgery*; D003390:Cranial Nerve Neoplasms / Q000175:diagnosis / Q000473:pathology / Q000601:surgery*; D003937:Diagnosis, Differential; D015174:Epidural Neoplasms / Q000175:diagnosis / Q000473:pathology / Q000601:surgery*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D009463:Neuroma / Q000175:diagnosis / Q000473:pathology / Q000601:surgery*; D010579:Petrous Bone / Q000294:innervation / Q000473:pathology / Q000601:surgery; D014057:Tomography, X-Ray Computed