Gall-bladder interposition: a rare anomaly of the extrahepatic ducts.

Abnormalities in bile ducts pattern occur frequently enough to merit importance during cholecystectomy. A patient with anomalous insertion of both hepatic ducts into the gall-bladder with the cystic duct replacing the common bile duct is described. This case, and related anomalies of the bile ducts, are sufficiently important for us to ascertain their location and pattern prior to removal of the gall-bladder. Inadvertent injury to a normal or aberrant bile duct can result in morbidity and even mortality. Knowledge of the embryogenesis of these anomalies helps in the understanding of the location and pattern of these malformations. Almost all of these unusual bile duct arrangements can be recognised by following the rules of meticulous dissection and accurate knowledge of these anatomical aberrations.