title: [Pathophysiology of cholesteatoma].
abstract: OBJECTIVE
  To describe the development of cholesteatoma using current knowledge.
  
  
  METHODS
  Review of the literature.
  
  
  RESULTS
  Cholesteatoma describes a mass of keratin (skin) in the middle ear which consists of a perimatrix and matrix. There are at least three kinds of cholesteatoma in the middle ear one resulting from invagination (retraction's pocket), another from migration and the last one from congenital inclusion. Cholesteatoma needs three successive inflammatory phases, the first leading to a retraction pocket, the second leading to pathology of the epidermis and of the floor of the external auditory canal and the third is the actual phase of cholesteatoma with invasion and middle ear auto-destruction with bone resorption. In this last phase, many factors play a role, collagenasis, osteoclats, cytokines, NO, bacteria and their biofilm and rupture of the retraction pocket.
  
  
  CONCLUSIONS
  Cholesteatoma is an inflammatory disease of the ear caracterised by bone resorption. Current research is starting to appreciate the important role the immune system plays in the pathophysiology of cholesteatoma.
authors.affiliation: Cliniques Universitaires Saint-Luc, Bruxelles, France. Denuit@orlo.ucl.ac.be
authors.forename: M C H
authors.initials: MC
authors.lastname: Gersdorff
authors.forename: M E
authors.initials: ME
authors.lastname: Debaty
authors.forename: J P
authors.initials: JP
authors.lastname: Tomasi
mesh_terms: D001419:Bacteria / Q000254:growth & development; D001424:Bacterial Infections / Q000276:immunology; D018441:Biofilms / Q000254:growth & development; D001862:Bone Resorption; D018424:Cholesteatoma, Middle Ear / Q000276:immunology / Q000382:microbiology / Q000503:physiopathology*; D016207:Cytokines / Q000276:immunology; D006801:Humans; D009569:Nitric Oxide / Q000502:physiology; D010010:Osteoclasts / Q000378:metabolism
chemical_list: D016207:Cytokines; D009569:Nitric Oxide