title: Cyst of the third ventricle as an unusual cause of acquired hydrocephalus.
abstract: Cysts of the third ventricle are rare congenital suprasellar malformations of arachnoidal, endodermal, or neuroepithelial origin. Depending on their size and location, they can cause space-occupying intracranial lesions and hydrocephalus occlusus by obstruction of the aqueduct or foramen of Monro. They can be missed on routine computer tomography and magnetic resonance imaging. A 2-year-old boy presented signs of intracranial pressure. Initial magnetic resonance imaging revealed a triventricular internal hydrocephalus with no visible etiologic lesion. An extended investigation with the constructive interference in steady state-technique showed a mobile cystic cerebrospinal fluid-intense lesion within the third ventricle, causing transient occlusion of the foramen of Monro. A suprasellar cyst of the third ventricle is an important differential diagnosis in apparently "idiopathic" internal hydrocephalus. In such cases, magnetic resonance imaging using the constructive interference in steady state-technique with a slice thickness of 1 mm is the method of choice for detecting intraventricular cysts. Neurosurgical fenestration and/or resection of the cyst by neuroendoscopy can resolve cerebrospinal fluid circulation disturbances and seems to be superior to a shunt.
authors.affiliation: Department of Pediatric Neurology, Johann Wolfgang GoetheUniversity, Frankfurt/Main, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Vlaho
authors.forename: Boris
authors.initials: B
authors.lastname: Gebhardt
authors.forename: Rüdiger
authors.initials: R
authors.lastname: Gerlach
authors.forename: Stephan
authors.initials: S
authors.lastname: Weidauer
authors.forename: Matthias
authors.initials: M
authors.lastname: Kieslich
mesh_terms: D002675:Child, Preschool; D003560:Cysts / Q000150:complications* / Q000175:diagnosis; D006801:Humans; D006849:Hydrocephalus / Q000175:diagnosis / Q000209:etiology*; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D020542:Third Ventricle / Q000473:pathology*