title: Development of a middle fossa arachnoid cyst. A theory on its pathogenesis.
abstract: The progression of congenital arachnoid cysts has seldom been documented. We report the case of a child who was diagnosed with arrested hydrocephalus at the age of 13 months. Neuroimaging studies performed when the girl was 22 months old showed the appearance of an arachnoid cyst in the right middle fossa, while the previously enlarged ventricles seemed to have decreased in size. To the best of our knowledge, the paradoxical expansion of an arachnoid pouch following a reduction in the size of the ventricular system has not previously been documented. We advance the hypothesis that the development of some cases of arachnoid cyst might be pathogenically related to impaired CSF dynamics associated with pre-existing hydrocephalus. We also briefly review the pertinent literature on the formation and evolution of congenital cerebral arachnoid cysts.
authors.affiliation: Section of Pediatric Neurosurgery, Virgen de la Arrixaca University Hospital, National Institute of Health, Murcia, Spain.
authors.forename: J F
authors.initials: JF
authors.lastname: Martínez-Lage
authors.forename: D
authors.initials: D
authors.lastname: Ruíz-Maciá
authors.forename: J A
authors.initials: JA
authors.lastname: Valentí
authors.forename: M
authors.initials: M
authors.lastname: Poza
mesh_terms: D016080:Arachnoid Cysts / Q000175:diagnosis* / Q000209:etiology* / Q000601:surgery; D015170:Cerebrospinal Fluid Pressure / Q000502:physiology; D002557:Cerebrospinal Fluid Shunts / Q000379:methods; D002648:Child; D002675:Child, Preschool; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006849:Hydrocephalus / Q000150:complications* / Q000628:therapy; D007223:Infant; D008279:Magnetic Resonance Imaging; D010537:Peritoneum; D012008:Recurrence; D012086:Reoperation; D019690:Technetium Tc 99m Exametazime; D013702:Temporal Lobe / Q000000981:diagnostic imaging / Q000601:surgery; D015899:Tomography, Emission-Computed, Single-Photon; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D014888:Wechsler Scales
chemical_list: D019690:Technetium Tc 99m Exametazime