title: Diagnosis and treatment of orbital optic nerve sheath meningioma.
abstract: BACKGROUND
  Primary and secondary optic nerve sheath meningiomas (ONSMs) are neoplasms that account for a large proportion of optic nerve and orbital tumors. The diagnosis is not always straightforward and is based on the appropriate clinical findings and neuroimaging. Biopsy or surgical intervention may occasionally be necessary but is associated with significant morbidity.
  
  
  METHODS
  Issues related to clinical signs and symptoms, diagnosis, natural history, and treatment strategies are reviewed based on a review of published literature.
  
  
  RESULTS
  Diagnosis is usually based on radiographic and clinical findings. Biopsies are not obtained in most cases, thus adding further to the bias of possible misdiagnosis in all reported case series that do not have the benefit of histopathologic confirmation. Natural history typically shows inexorable progression in most cases, although long periods of stability are occasionally reported. Treatment options include observation, radiation alone, surgery alone, and combined radiation and surgery. The optimum timing of interventional therapy and radiation are evolving.
  
  
  CONCLUSIONS
  After serial examination documents new decline in acuity and/or visual field, fractionated radiotherapy appears most likely to preserve visual function and is a valid treatment approach for primary orbital ONSM. Tumor enlargement, as determined by serial imaging, may also provide an indication to begin radiotherapy.
authors.affiliation: University of Medicine and Dentistry of New Jersey, New Jersey Medical School, Newark, NJ 07103, USA. turbinre@umdnj.edu
authors.forename: Roger E
authors.initials: RE
authors.lastname: Turbin
authors.forename: Kathryn
authors.initials: K
authors.lastname: Pokorny
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008297:Male; D008579:Meningioma / Q000175:diagnosis* / Q000453:epidemiology / Q000628:therapy*; D008875:Middle Aged; D013508:Ophthalmologic Surgical Procedures / Q000379:methods; D019574:Optic Nerve Neoplasms / Q000175:diagnosis* / Q000453:epidemiology / Q000628:therapy*; D011379:Prognosis; D011878:Radiotherapy / Q000379:methods; D017678:Sex Distribution; D016896:Treatment Outcome