Differential Diagnosis of Periampullary Carcinomas at MR Imaging

Abstract

Periampullary carcinomas arise within 2 cm of the major duodenal papilla and comprise carcinomas of the ampulla, distal common bile duct, pancreas, and duodenum. Their clinical features and anatomic locations are similar, as are the therapeutic approaches; however, their long-term outcomes vary. Magnetic resonance (MR) images of 89 pathologically proved periampullary carcinomas (29 ampullary carcinomas, 27 distal common bile duct carcinomas, 21 pancreatic carcinomas, six duodenal carcinomas, and six unclassified carcinomas) were reviewed. Ampullary carcinoma manifests as a small mass, periductal thickening, or bulging of the duodenal papilla. Pancreatic carcinoma is characterized by a discrete parenchymal mass, which enhances poorly on dynamic gadolinium-enhanced images. Sometimes, two proximal and two distal pancreatic and biliary ducts appear as four separate ducts (the four-segment sign). Dilatation of side branches of the pancreatic ducts is frequently seen in pancreatic carcinoma but not in other periampullary carcinomas. Distal bile duct carcinoma manifests as luminal obliteration and wall thickening or as an intraductal polypoid mass. A dilated proximal bile duct, a nondilated distal bile duct, and a dilated or nondilated pancreatic duct may form the three-segment sign. MR cholangiopancreatography and sectional MR imaging are useful in determining the origins of periampullary carcinomas.

Differential Features of Pancreatobiliary- and Intestinal-type Ampullary Carcinomas at MR Imaging

“…Ampullary carcinoma can manifest as either a nodular (polypoid) or an infi ltrative (periductal thickening) mass on MR images ( 21 ). In our study, all of the intestinal-type carcinomas were nodular, whereas 16 (46%) of 35 pancreatobiliarytype carcinomas were infi ltrative.…”

“…Papillary bulging is a useful fi nding for differentiating ampullary carcinoma from benign ampullary stricture ( 21 ). In a previous study, 65%-95% of ampullary carcinomas showed papillary bulging, compared with only 14% of benign ampullary obstructions ( 21 ).…”

“…Several imaging findings typical of ampullary carcinoma have been reported, including ampullary mass, papillary bulging, irregular and asymmetric narrowing of the common bile duct (CBD), and proportional biliary dilatation ( 21,22 ). To our knowledge, investigators in no study have attempted to differentiate the microscopic types of ampullary carcinoma by using preoperative MR imaging.…”

Clinical practice guidelines for the management of biliary tract cancers 2015: the 2nd English edition

“…Bile duct dilatation with pancreatic duct dilatation (double-duct sign) indicates the existence of the ampullary carcinoma. However this sign is not specific for the ampullary carcinoma as the pancreatic head carcinoma also often shows the same sign [43].…”

Comprehensive management of cholangiocarcinoma: Part I. Diagnosis

“…However, presence of a mass in the distal common bile duct that does not invade the bile duct or does not cause thickening of the duct wall strongly favors pancreatic cancer. 48 In cases of MRI suboptimal special resolution or motion artifacts, multi-detector CT (MDCT) has a negative predictive value between 85% and 100% and may be useful as a secondary imaging modality. CT should include arterial and portal venous phase and should include the pelvis and the thorax if tumor staging is warranted.…”