Choledochocele: importance of histological evaluation.

Choledochocele is a rare abnormality of unknown etiology that consists of cystic or diverticular dilatations of the intramural part of the common bile duct. The authors present a case of choledochocele with a common channel in a 15-year-old boy who had a 5-year history of intermittent right upper abdominal pain. In a review of the literature, macroscopic variations were noted as well as different types of epithelial lining inside the choledochocele. Whereas in young children mostly duodenal mucosa is described, biliary tract epithelium and undifferentiated epithelium are predominant later on. Etiologically, congenital intraluminal duodenal diverticulum should be suggested in relation to the pathogenesis of choledochocele. Treatment is total excision and reinsertion of both ducts in cases of biliary or undifferentiated epithelium; endoscopic sphincterotomy or marsupialization is indicated only when duodenal mucosa covers both sides of the choledochocele.