title: Extrahepatic right hepatic duct diverticulum: a rare entity.
abstract: BACKGROUND
  Douglas described choledochal cysts in 1852 and Todani proposed an anatomy-based classification in 1977. The classification is the most extensively used, but does not include some rare variations. We present a case of hepatic duct diverticulum, one of the variations, and discuss its diagnosis and treatment.
  
  
  METHODS
  A 57-year-old woman presented with upper abdominal pain and discomfort associated with nausea and vomiting. She was finally diagnosed with cholelithiasis and right hepatic duct diverticulum.
  
  
  RESULTS
  The patient underwent resection of the hepatic duct diverticulum and cholecystectomy, and was asymptomatic 26 months after surgery.
  
  
  CONCLUSIONS
  Hepatic duct diverticulum is a rare form of choledochal cyst, not included in Todani's classification. Todani's classification including this and other uncommon variations of choledochal cysts must be reviewed. The best diagnostic imaging methods and treatment for choledochal cysts must be defined.
authors.affiliation: Department of General Surgery, Section of Hepatobiliary Surgery and Transplantation, Rio de Janeiro Federal University, Rio de Janeiro, Brazil.
authors.forename: Eduardo S M
authors.initials: ES
authors.lastname: Fernandes
authors.forename: Raquel L
authors.initials: RL
authors.lastname: Bernardo
authors.forename: Moacir M
authors.initials: MM
authors.lastname: Fernandes
authors.forename: Rogério M C
authors.initials: RM
authors.lastname: Araújo
authors.forename: Renato
authors.initials: R
authors.lastname: Sebbe
authors.forename: Asterio
authors.initials: A
authors.lastname: Monte
authors.forename: José F
authors.initials: JF
authors.lastname: Coelho
authors.forename: Antonio A P
authors.initials: AA
authors.lastname: Souza
authors.forename: Joaquim
authors.initials: J
authors.lastname: Ribeiro Filho
mesh_terms: D001649:Bile Duct Diseases / Q000175:diagnosis* / Q000628:therapy; D004240:Diverticulum / Q000175:diagnosis* / Q000628:therapy; D005260:Female; D006500:Hepatic Duct, Common; D006801:Humans; D008875:Middle Aged