title: Intracranial arachnoid cyst.
abstract: BACKGROUND
  Arachnoid cysts (ACs) contain a liquid similar to cerebrospinal fluid. Some communicate with the subarachnoid space and others do not. These cysts are reported to account for at least 1% of all intracranial mass lesions. Most patients present during the first two decades of life; however, presentation during adulthood is not uncommon.
  
  
  CONCLUSIONS
  A literature review to identify studies relating to pathogenesis, epidemiology, genetics, presentation, radiology and treatment of ACs was conducted and indicated that symptoms depend on size and location. When ACs are symptomatic, they must be treated surgically. Surgical treatment of ACs can be accomplished by cystoperitoneal shunting or fenestration of the cyst either by craniotomy or endoscopic techniques.
  
  
  CONCLUSIONS
  Currently, appropriate treatment is still controversial regarding which is the best technique. Expectative treatment should be considered in lower volume cysts and, even more, in asymptomatic patients diagnosed by other studies.
authors.affiliation: Servicio de Neurocirugía, Hospital General Naval de Alta Especialidad, Secretaría de Marina, México, D. F., Mexico. drvega@neurocirugia.com
authors.forename: Alfonso
authors.initials: A
authors.lastname: Vega-Sosa
authors.forename: Enrique
authors.initials: E
authors.lastname: de Obieta-Cruz
authors.forename: Manuel Alejandro
authors.initials: MA
authors.lastname: Hernández-Rojas
mesh_terms: D016080:Arachnoid Cysts / Q000175:diagnosis / Q000209:etiology / Q000601:surgery; D006801:Humans