IgG4-Related Sclerosing Cholangitis: A Diagnostic Dilemma

Abstract

Immunoglobulin G4-related disease is a rare yet newly recognized immune-mediated process that affects multiple organs including the biliary tract1. Key features include lymphocytic infiltration of IgG4 plasma cells and tumor-like swelling of the affected organ2,3. IgG4-related sclerosing cholangitis has variable presentations but most commonly presents with obstructive jaundice, weight loss, and biliary strictures which makes it challenging to differentiate between cholangiocarcinoma3,4. Having a high clinical suspicion of IgG4-related sclerosing cholangitis is essential as it may prevent patients from undergoing extensive surgery in pursuit of a malignancy. We report a case of a patient who presented with obstructive jaundice and weight loss with dilated common bile duct and thus was thought to have cholangiocarcinoma. He underwent a Whipple's procedure but was later diagnosed with IgG4- related sclerosing cholangitis. A 67 year old man presented with a 2 week history of painless jaundice and 20 pound unintentional weight loss with labs notable for alk phos 600s, ALT/AST 700s, and Tbili 15. CT scan showed mild intrahepatic dilation and distal common bile duct dilation to 1.2cm. No pancreatic or hepatic masses were seen. ERCP showed a 2 cm severe stricture in the lower third of the common bile duct with dilation of the upstream ducts. EUS showed 2mm wall thickening in the distal common bile duct extending to the mid duct. The pancreatic duct was not dilated. Cytology brushings were negative for malignancy. He underwent a Whipple's procedure due to concern of cholangiocarcinoma. Post-operatively, his liver function tests normalized and he was discharged. Final pathology showed IgG4-related sclerosing cholangitis. He was readmitted 1 month later with obstructive jaundice. MRCP showed moderate dilation of the right intrahepatic biliary duct. Serum IgG4 levels were elevated at 163 mg/dl. He was started on steroids with normalization of his liver function tests and resolution of biliary ductal dilation and stricture. This case highlights the difficulty in differentiating cholangiocarcinoma from IgG4-related sclerosing cholangitis; yet, the distinction is important as the management for both diseases is completely different. In retrospect, if one had had a high level of clinical suspicion for IgG4-sclerosing cholangitis, checking an IgG4 serum level may have prevented the patient from undergoing an invasive procedure, the Whipple's surgery.