title: The difference in congenital cholesteatoma CT findings based on the type of mass.
abstract: OBJECTIVE
  A retrospective assessment of differences in congenital cholesteatoma CT findings with a focus on type of cholesteatoma mass.
  
  
  METHODS
  The medical records and CT images of 14 patients with congenital cholesteatomas in the middle ear who underwent surgery at our institution between January 2009 and July 2014 were reviewed. Cholesteatomas were classified as closed type, open type, or mixed type based on intraoperative findings. The CT findings including cholesteatoma size, location, and shape were retrospectively reviewed.
  
  
  RESULTS
  Eight patients had closed type cholesteatomas, four had mixed type, and two had open type. The mean size of all cholesteatomas was 5.1mm. None of the cholesteatoma types indicated a tendency towards a certain location. The round shape was observed more frequently in closed type cholesteatomas than in other types (closed: 5/8; mixed: 1/4; open: 0/2). Two large closed type cholseteatomas and two mixed type cholesteatomas exhibited a constricted shape. Both of the open type cholesteatomas displayed an irregular shape.
  
  
  CONCLUSIONS
  Small closed type congenital cholesteatomas were typically observed as round shaped lesions, but large closed type cholesteatomas and other type cholesteatomas tended to display shapes other than round.
authors.affiliation: Department of Radiology, Okayama University Medical School, 2-5-1 Kitaku Shikatacho, Okayama 700-8558, Japan. Electronic address: tada-a@cc.okayama-u.ac.jp.
authors.forename: A
authors.initials: A
authors.lastname: Tada
authors.affiliation: Department of Radiology, Okayama University Medical School, 2-5-1 Kitaku Shikatacho, Okayama 700-8558, Japan. Electronic address: mogmog@jb3.so-net.ne.jp.
authors.forename: R
authors.initials: R
authors.lastname: Inai
authors.affiliation: Department of Radiology, Okayama University Medical School, 2-5-1 Kitaku Shikatacho, Okayama 700-8558, Japan. Electronic address: takaikokorozashi@hotmail.com.
authors.forename: T
authors.initials: T
authors.lastname: Tanaka
authors.affiliation: Department of Radiology, Okayama University Medical School, 2-5-1 Kitaku Shikatacho, Okayama 700-8558, Japan. Electronic address: marukawayouhei@yahoo.co.jp.
authors.forename: Y
authors.initials: Y
authors.lastname: Marukawa
authors.affiliation: Department of Radiology, Okayama University Medical School, 2-5-1 Kitaku Shikatacho, Okayama 700-8558, Japan. Electronic address: shuhei@cc.okayama-u.ac.jp.
authors.forename: S
authors.initials: S
authors.lastname: Sato
authors.affiliation: Otolaryngology, Okayama University Medical School, 2-5-1 Kitaku Shikatacho, Okayama 700-8558, Japan. Electronic address: nishizak@cc.okayama-u.ac.jp.
authors.forename: K
authors.initials: K
authors.lastname: Nishizaki
authors.affiliation: Department of Radiology, Okayama University Medical School, 2-5-1 Kitaku Shikatacho, Okayama 700-8558, Japan. Electronic address: susumu@cc.okayama-u.ac.jp.
authors.forename: S
authors.initials: S
authors.lastname: Kanazawa
mesh_terms: D002648:Child; D002675:Child, Preschool; D018424:Cholesteatoma, Middle Ear / Q000145:classification / Q000151:congenital* / Q000000981:diagnostic imaging* / Q000473:pathology; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed
keywords: Closed type; Computed tomography; Congenital cholesteatoma; Middle ear; Open type