title: Aquaporin(s) expression in choroid plexus tumours.
abstract: OBJECTIVE
  It was the aim of this study to investigate the pattern of aquaporin 1 (AQP1) expression in normal and neoplastic choroid plexus, with specific reference to the association with communicating hydrocephalus or liquoral cysts. Second, to infer a new view on the cerebrospinal fluid plexus production and on the etiology of the cysts and communicating hydrocephalus occasionally associated with choroid plexus papillomas.
  
  
  METHODS
  Nineteen paraffin-embedded specimens, 10 of normal choroid plexus and 9 of choroid plexus tumours, were immunostained with a monoclonal antibody raised against the intracellular C-terminal AQP1 epitope. Results were analysed in terms of intensity and intracellular distribution of immunostaining and in terms of number of stained cells; they were considered in light of the clinical association with hydrocephalus or liquoral cysts.
  
  
  RESULTS
  AQP1 was heavily expressed in the apical side of the choroid epithelium in normal plexus specimens. Choroid plexus papillomas showed a very heterogeneous pattern of AQP1 expression. Immunostaining was absent in the case of choroid plexus carcinoma. Very strong to strong and diffuse AQP1 expression in large to very large papillomas was associated with liquoral cysts or communicating hydrocephalus.
  
  
  CONCLUSIONS
  AQP1 expression characterizes normal choroid plexus and plexus papillomas. Intensity and diffusion of AQP1 expression together with the size of the tumour mass are somewhat predictive of communicating hydrocephalus or liquoral cyst, lesions possibly caused by a disturbance of cerebrospinal fluid homeostasis.
authors.affiliation: Neurosurgery Unit, Treviso Hospital, Treviso, Italy.
authors.forename: Pierluigi
authors.initials: P
authors.lastname: Longatti
authors.forename: Luca
authors.initials: L
authors.lastname: Basaldella
authors.forename: Enrico
authors.initials: E
authors.lastname: Orvieto
authors.forename: Angelo
authors.initials: A
authors.lastname: Dei Tos
authors.forename: Andrea
authors.initials: A
authors.lastname: Martinuzzi
mesh_terms: D051398:Aquaporin 1 / Q000378:metabolism*; D016545:Choroid Plexus Neoplasms / Q000378:metabolism* / Q000473:pathology; D042783:Endothelial Cells / Q000378:metabolism; D006801:Humans; D006849:Hydrocephalus / Q000150:complications; D020288:Papilloma, Choroid Plexus / Q000150:complications / Q000378:metabolism* / Q000473:pathology; D012189:Retrospective Studies
chemical_list: D051398:Aquaporin 1