title: Locations of congenital cholesteatoma in the middle ear in Japanese patients.
abstract: OBJECTIVE
  To present clinical features of congenital cholesteatoma treated in our institute and to investigate the locations of congenital cholesteatoma in the middle ear of Japanese patients to verify its pathogeneses.
  
  
  METHODS
  A retrospective chart review of patients in our institute and a review of articles on congenital cholesteatoma reported by Japanese researchers. Charts of the 25 patients with congenital cholesteatoma treated in our institute were reviewed regarding symptoms, locations of cholesteatoma in the middle ear, and ossicular anomalies. The same points were investigated in the 71 cases in the Japanese literature.
  
  
  RESULTS
  Unlike Westerners, more than half of the Japanese cases had posterior-type cholesteatomas, any parts of which did not exist anteriorly beyond the handle of the malleus. Congenital ossicular anomalies, absence of the long process of the incus, and/or the superior structure of the stapes were seen with a high rate in the Japanese patients.
  
  
  CONCLUSIONS
  These two findings of the posterior location of cholesteatomas in the middle ear and the high incidence of congenital ossicular anomalies in the Japanese patients suggested that there should be some racial difference in pathogenesis of congenital cholesteatoma. The pathogenesis of congenital cholesteatoma cannot be adequately explained by only one theory alone. It is more appropriate to explain the pathogenesis by using an aggregation of theories.
authors.affiliation: Department of Otolaryngology, Head and Neck Surgery, Hokkaido University Graduate School of Medicine, Sapporo, Japan. true-north@eva.hi-ho.ne.jp
authors.forename: Masaaki
authors.initials: M
authors.lastname: Kashiwamura
authors.forename: Satoshi
authors.initials: S
authors.lastname: Fukuda
authors.forename: Eiji
authors.initials: E
authors.lastname: Chida
authors.forename: Michiya
authors.initials: M
authors.lastname: Matsumura
mesh_terms: D044466:Asian People; D002648:Child; D002675:Child, Preschool; D018424:Cholesteatoma, Middle Ear / Q000151:congenital / Q000208:ethnology* / Q000473:pathology*; D004429:Ear Ossicles / Q000002:abnormalities; D005260:Female; D034381:Hearing Loss / Q000209:etiology; D006801:Humans; D007223:Infant; D008297:Male; D012189:Retrospective Studies