Preduodenal portal vein: a potential laparoscopic cholecystectomy nightmare.

Variations of biliary anatomy are well described. Those of most relevance to the operative surgeon are the variations of the extrahepatic ducts and their relationships to the right hepatic artery and its branches. We describe another even rarer congenital anomaly of a preduodenal portal vein. Its embryological derivation and presentation are discussed to heighten awareness of its recognition and reduce the potential of a serious operative misadventure.