Gas in the biliary tree on plain abdominal X-ray is suggestive of:: (A) Empyema of the gallbladder, (B) Mirizzi syndrome, (C) Biliary enteric fistula, (D) Porcelain gallbladder
Answer is C. Clinically "silent" biliary-enteric fistulas occurring as a complication of acute cholecystitis and it can be diagnosed by finding gas in the biliary tree on plain abdominal films. Barium contrast studies or endoscopy of the upper gastrointestinal tract or colon may demonstrate the fistula. Reference: Harrisons Principles of Internal Medicine, 18th Edition, Page 2622