title: Hemorrhagic vestibular schwannoma: review of the literature.
abstract: BACKGROUND
  Clinically significant intratumoral hemorrhage historically has been reported in only a small fraction of vestibular schwannomas (VS). Patients with hemorrhagic VS are more likely to present with neurologic deficits and have worse outcomes than patients with nonhemorrhagic VS. The purpose of this study is to analyze characteristics that may predispose VS to hemorrhage and that may prove helpful in the management and treatment of VS.
  
  
  METHODS
  A literature search was conducted using National Library of Medicine and National Institutes of Health databases to identify articles pertaining to intratumoral hemorrhage in VS. The authors selected 39 cases, described in 18 published articles, to review.
  
  
  RESULTS
  Average patient age and tumor size in hemorrhagic cases of VS did not differ significantly from nonhemorrhagic cases of VS. Facial nerve dysfunction at presentation occurred with greater frequency in cases of hemorrhagic VS (33.3%) than in nonhemorrhagic VS (6.0%). Death occurred much more frequently in cases of hemorrhagic VS (10.0%) than in nonhemorrhagic VS (0.2%). Abnormality of tumor-associated vasculature was noted histologically in many cases, and a large number of the cases reported prior treatment by stereotactic radiosurgery.
  
  
  CONCLUSIONS
  Understanding the origins and clinical implications of intratumoral hemorrhage in VS could potentially assist in clinical decision making and patient counseling.
authors: Department of Neurosurgery, University of Michigan, Ann Arbor, Michigan, USA.
authors: Yashar S
authors: YS
authors: Niknafs
authors: Department of Neurosurgery, University of Michigan, Ann Arbor, Michigan, USA.
authors: Anthony C
authors: AC
authors: Wang
authors: Department of Neurosurgery, University of Michigan, Ann Arbor, Michigan, USA.
authors: Khoi D
authors: KD
authors: Than
authors: Department of Neurosurgery, University of Michigan, Ann Arbor, Michigan, USA.
authors: Arnold B
authors: AB
authors: Etame
authors: Department of Neurosurgery, University of Michigan, Ann Arbor, Michigan, USA.
authors: B Gregory
authors: BG
authors: Thompson
authors: Department of Neurosurgery, University of Michigan, Ann Arbor, Michigan, USA. Electronic address: ssulliva@med.umich.edu.
authors: Stephen E
authors: SE
authors: Sullivan
mesh_terms: D006801:Humans; D020300:Intracranial Hemorrhages / Q000175:diagnosis / Q000209:etiology / Q000601:surgery; D009464:Neuroma, Acoustic / Q000150:complications / Q000175:diagnosis / Q000601:surgery; D016634:Radiosurgery / Q000009:adverse effects / Q000379:methods*; D000159:Vestibulocochlear Nerve / Q000601:surgery*
keywords: Acoustic neuroma; Intratumoral hemorrhage; Vestibular schwannoma