A giant duodenal diverticulum causing Lemmel syndrome.

An 80-year-old female, with a known periampullary giant duodenal diverticulum, presented to the emergency department with general deterioration. While not clinically icteric, her laboratory investigations revealed an obstructive jaundice. MRCP demonstrated mild distension of the gallbladder with several calculi. There was intra- and extra-hepatic biliary dilatation to the level of the ampulla. A giant fluid and air filled periampullary duodenal diverticulum measuring ~8 cm in the long axis was noted. The CBD was dilated to the level of this diverticulum and the cause of the patient's biliary dilatation and obstruction. A rare pancreaticobiliary complication of duodenal diverticula is Lemmel syndrome. Lemmel syndrome is defined as an obstructive jaundice caused by a periampullary duodenal diverticulum compressing the intra-pancreatic portion of the common bile duct with resultant dilatation of the extra- and intra-hepatic bile ducts. Recognition of this condition is important, as delayed diagnosis can result in unnecessary further investigations.