Ascaris in the common bile duct: diagnosis by ultrasound and endoscopic retrograde cholangiopancreatography (ERCP) and extraction by balloon catheter.

This is a case report of ascaris worm in the common bile duct in a 61 year old lady. Ultrasound diagnosis was initially made based on the presence of linear hyperreflective foci within the common bile duct. ERCP confirmed a single worm within the duct. Balloon extraction was then successfully carried out following papillotomy. This case illustrates the value of ultrasound in the definitive diagnosis of biliary ascariasis and the therapeutic role of ERCP.