DUODENAL DIVERTICULUM

85 yrs male with history of fall

Axial plain CT section through pancreas: well defined airpocket with adjacent solid debris noted potero medial to head of pancreas (coronal reformation showed this as outpouching from 3rd part of duodenum)- s/o incidental duodenal diverticulum.

·        Duodenal diverticula are common and are incidentally discovered.

·        Most are acquired, rather than congenital, abnormalities.

·        Easily recognized on upper gastrointestinal barium examinations as collections of gas and barium in round or oval sacklike protrusions that usually arise from the medial aspect of the periampullary duodenum.

·        The typical CT appearance of a duodenal diverticulum has been described as a thin-walled rounded collection of gas and oral contrast material situated along the medial border of the junction of the second and third portions of the duodenum.

·        On T2-weighted MR imaging, duodenal diverticula may contain both high-signal-intensity areas (related to the presence of fluid) and low-signal-intensity areas (related to the presence of gas).

·        Duodenal diverticula are rarely symptomatic, although they may make cannulation of the common bile duct difficult during an ERCP or may become impacted with debris, leading to duodenal diverticulitis.

·        Complications of hemorrhage and increased prevalence of choledocholithiasis have been described.

·        Misinterpretation of a duodenal diverticulum on CT as a pancreatic tumor, metastatic lymph node, pancreatic pseudocyst, or pancreatic abscess has been reported.

·        One may be unable to distinguish duodenal diverticula on CT or MR imaging if their content is purely fluid.

·        The differential diagnosis of a cystic lesion in the region of the head of the pancreas includes cystic pancreatic neoplasms, inflammatory processes (such as pseudocysts), and duodenal diverticula.

·        Three cystic tumors are relatively common pancreatic neoplasms—an intraductal papillary mucinous neoplasm, mucinous cystic neoplasm, and serous cystic neoplasm.

Reference: Duodenal Diverticula Mimicking Cystic Neoplasms of the Pancreas: CT and MR Imaging Findings in Seven Patients, AJR January 2003 vol. 180 no. 1 195-199.