Abrupt termination of the common bile duct: a sign of malignancy identified by high-resolution real-time sonography.

Although contrast cholangiography has a greater accuracy than sonography in determining the precise nature of extrahepatic biliary obstruction, it is not without risk. High-resolution real-time sonography is frequently adequate to evaluate the extrahepatic biliary system in multiple planes without known risk to the patient. In a one-year period the authors prospectively observed eight instances of distal biliary obstruction with abrupt termination of the common bile duct, and all were associated with malignant obstruction. There was no instance of abrupt ductal termination secondary to benign disease in this series. Malignancy should be suspected when careful sonograms along the longitudinal axis of an obstructed distal common bile duct reveal an abrupt termination.