title: Practicality analysis of the staging system proposed by the Japan Otological Society for acquired middle ear cholesteatoma: A multicenter study of 446 surgical cases in Japan.
abstract: OBJECTIVE
  The Objective of this study was to assess the practicality of the cholesteatoma staging system proposed by the Japan Otological Society (JOS) for acquired middle ear cholesteatoma (the 2010 JOS staging system).
  
  
  METHODS
  Between 2009 and 2010, 446 ears with retraction pocket cholesteatoma underwent primary surgery at 6 institutions in Japan. The extent of cholesteatoma was surgically confirmed, and classified into three stages.
  
  
  RESULTS
  The cholesteatoma affected the pars flaccida in 325 ears (73%), the pars tensa in 100 ears (22%), and both regions combined in 21 ears (5%). The hearing outcome (postoperative air-bone gaps dB) worsened as follows (Stage I, II, III): 84%, 68%, 53% in pars flaccida; 71%, 62%, 30% in pars tensa, and 42% at Stage II, and 50% at Stage III in the combined group. The incidence of residual cholesteatoma increased as follows (Stage I, II, III): 2%, 12%, 23% in pars flaccida; 7%, 30%, 21% in the pars tensa group. The severity of disease was reflected in postoperative hearing and increasing incidence of recurrence rate.
  
  
  CONCLUSIONS
  The 2010 JOS staging system is suitable for evaluating initial pathology. It is particularly practical for standardizing reporting of retraction pocket cholesteatoma and for adjusting for the severity of the condition during outcome evaluations. It may also provide information that is useful for counseling patients.
authors.affiliation: Department of Otorhinolaryngology - Head & Neck Surgery, University of Miyazaki, Japan. Electronic address: kmatsuda@med.miyazaki-u.ac.jp.
authors.forename: Keiji
authors.initials: K
authors.lastname: Matsuda
authors.affiliation: Department of Otorhinolaryngology - Head & Neck Surgery, University of Miyazaki, Japan. Electronic address: tono@med.miyazaki-u.ac.jp.
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Tono
authors.affiliation: Department of Otorhinolaryngology, Jikei University School of Medicine, Japan. Electronic address: kojimah@jikei.ac.jp.
authors.forename: Hiromi
authors.initials: H
authors.lastname: Kojima
authors.affiliation: Department of Otolaryngology Head and Neck Surgery, Niigata University Faculty of Medicine, Japan. Electronic address: entyama@jikei.ac.jp.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Yamamoto
authors.affiliation: Department of Otorhinolaryngology - Head and Neck Surgery, Hyogo College of Medicine, Japan. Electronic address: msakaga@hyo-med.ac.jp.
authors.forename: Masafumi
authors.initials: M
authors.lastname: Sakagami
authors.affiliation: Department of Otorhinolaryngology - Head and Neck Surgery, Hyogo College of Medicine, Japan. Electronic address: ymishiro@hyo-med.ac.jp.
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Mishiro
authors.affiliation: Department of Otorhinolaryngology, Showa University School of Medicine, Kamio Memorial Hospital, Japan. Electronic address: hinohira@med.showa-u.ac.jp.
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Hinohira
authors.affiliation: Department of Otorhinolaryngology, Mitsui Memorial Hospital, Japan. Electronic address: tokuno503@gmail.com.
authors.forename: Taeko
authors.initials: T
authors.lastname: Okuno
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D018424:Cholesteatoma, Middle Ear / Q000145:classification* / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D005260:Female; D006801:Humans; D007564:Japan; D008297:Male; D008416:Mastoid / Q000000981:diagnostic imaging / Q000473:pathology; D008875:Middle Aged; D012189:Retrospective Studies; D012720:Severity of Illness Index; D013199:Stapes / Q000473:pathology; D014057:Tomography, X-Ray Computed
keywords: Acquired; Cholesteatoma; Multicenter; Outcomes; Staging