An ultrasound examination shows dilated intrahepatic biliary channels with a small gall bladder. The most likely possibility is: (A) Gall bladder stone, (B) Pancreatic calculus, (C) Common bile duct stone, (D) Carcinoma of the head of the pancreas
Answer is C. In obstruction of the CBD due to a stone,distension of gallbladder seldom occurs.The organ is usually shrivelled.In obstruction from other causes ,distension of gallbladder is common by comparison. Reference:Bailey & Love's sho practise of surgery,25th edition,page no:1125