title: Epidemiology, presentation, diagnosis, and outcomes of choledochal cysts in adults in an urban environment.
abstract: BACKGROUND
  Choledochal cysts (CDC) are rare congenital cystic lesions of the biliary tract. In North America the incidence of CDC is estimated as 1/150,000; it is not clear that the disease pattern in North America is similar to that in Asia.
  
  
  METHODS
  Retrospective chart review. Statistical analysis was under taken using Fisher's exact test.
  
  
  RESULTS
  Presentation, epidemiology, diagnosis, and outcome were evaluated in 51 patients with CDC. Malignant transformation was identified in 4 patients presenting uniformly with jaundice (P = .027). Type 4a cysts (54.9%) were the most common cyst identified. Four (14%) type IVa and two (13%) type I cysts developed postoperative stricture. No patient developed cholangiocarcinoma after complete resection of their cyst.
  
  
  CONCLUSIONS
  Types I and IVa cysts can be treated similarly with excellent outcome. However, our observation of a high proportion of type 4a cysts may represent a specific North American pattern of this disease requiring a re-evaluation of the classification system.
authors.affiliation: Section of Hepatobiliary Surgery, Department of Surgery, University of British Columbia, Vancouver BC, Canada.
authors.forename: Kevin
authors.initials: K
authors.lastname: Wiseman
authors.forename: Andrzej K
authors.initials: AK
authors.lastname: Buczkowski
authors.forename: Stephen W
authors.initials: SW
authors.lastname: Chung
authors.forename: Jason
authors.initials: J
authors.lastname: Francoeur
authors.forename: David
authors.initials: D
authors.lastname: Schaeffer
authors.forename: Charles H
authors.initials: CH
authors.lastname: Scudamore
mesh_terms: D000328:Adult; D001955:British Columbia / Q000453:epidemiology; D015529:Choledochal Cyst / Q000175:diagnosis / Q000453:epidemiology / Q000473:pathology* / Q000601:surgery*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D012189:Retrospective Studies; D014505:Urban Population