IgG4-related autoimmune cholangitis, pancreatitis, and pseudotumor
Presentation
Abdominal pain, elevated biliary enzymes.
Patient Data
Presentation CT
Multifocal intrahepatic biliary dilation, strictures, and irregularity. Soft tissue thickening and narrowing of the common bile duct. Some inflammatory changes of the pancreatic tail with surrounding fluid/early collections. Splenic vein occlusion with short gastric collaterals.
Presentation MRI
Multifocal intrahepatic biliary strictures leading into areas of wall thickening and patchy enhancement. Ill-defined mass-like enhancement in the central liver with pronounced thickening and enhancement of the common hepatic and common bile duct. Small pseudocyst near the pancreatic tail.
Presentation ERCP
Multifocal intra and extrahepatic biliary ductal strictures and dilation. Placement of a plastic biliary stent.
2 month post-treatment ERCP
Significant improvement of multifocal biliary stricturing and irregularity following treatment with steroids.
Case Discussion
This patient presented with a central biliary obstruction that is most concerning for a cholangiocarcinoma, but there are some clues that help to lead you to the correct diagnosis. First, notice the pancreatitis in the original CT mostly involving the pancreatic tail. This is due to autoimmune pancreatitis, which is often seen when you encounter autoimmune cholangitis.
Second, while the degree of smooth wall thickening and enhancement of the common hepatic and intrahepatic bile ducts can be seen with periductal infiltrating cholangiocarcinoma, I would have expected some other features of an advanced cholangiocarcinoma - specifically, some enlarged regional/porta hepatis lymph nodes or even signs of peritoneal disease. Plus, long segment involvement of the common bile duct is fairly typical of autoimmune cholangitis.
After the ERCP brushings/biopsy were negative for carcinoma, IgG4 levels were checked and found to be mildly elevated. Of note, this patient had substantially elevated CA 19-9, which kept the treatment team more concerned about cancer, prompting another biopsy of the central liver under ultrasound - also negative for cancer but with some nonspecific inflammatory findings. Following these negative biopsies, this patient underwent a trial therapy of steroids, with dramatic improvement of the biliary ductal dilation after about 2 months, confirming the presumptive diagnosis of IgG4-related cholangitis, pancreatitis, and hepatic pseudotumor.