S3439 Cavernous Transformation of the Portal Vein Mimicking a Biliary Mass in a JAK2-Positive Patient

Introduction: Portal cholangiopathy (PC) occurs as a result of extrinsic obstruction of the biliary tract due to engorged collateral veins in the hepatic hilum. These collateral veins, called portal cavernoma, can form due to increased pressure in the setting of portal vein thrombosis (PVT). In 2%-4% of patients with PC, end stage liver disease may result. We present a case of a patient with PC and subsequent sequelae of end stage liver disease. Case Description/Methods: A 68-year-old man presented for evaluation of elevated total bilirubin. Magnetic resonance imaging abdomen revealed a 4.4 × 3.9 cm × 5.6 cm periportal mass encasing the extrahepatic common bile duct with biliary obstruction, cirrhotic liver, splenomegaly, and splenic varices with a splenorenal shunt. Esophagogastroduodenoscopy/endoscopic retrograde cholangiopancreatography (ERCP)/endoscopic ultrasound (EUS) revealed Grade 4 esophageal varices status post EVL, portal hypertensive gastropathy, and a 2.5 cm porta hepatis lesion compressing the common bile duct. Doppler studies revealed the lesion was vascular and no FNA was performed. Sphincterotomy and spyglass cholangioscopy showed varices within the bile duct without a mass, consistent with PC. Post procedure, the patient developed abdominal pain, nausea, vomiting, and lipase of 3040. Computed tomography abdomen/pelvis without contrast showed chronic PVT, cavernous transformation, biliary ductal dilation, and narrowing at the hepatic duct confluence from extrinsic compression by the cavernous transformation of the main portal vein versus involvement from the soft tissue mass extending from the pancreatic head to the porta hepatis. The patient was noted to be hepatitis B core Ab and surface Ab positive. A repeat EUS was done with biopsy of the mass consistent with benign pancreatic tissue with a component of collateral vessels. It was suspected that the etiology of the patient’s portal hypertension was primarily due to PVT and cavernous formation. The patient was found to have a JAK2 mutation. Discussion: While uncommon, PC must be considered in patients presenting with sequelae of end stage liver disease without clear etiology and or patients presenting with biliary masses. Early intervention of PC with portosystemic shunt decompression, or in severe cases hepaticojejunostomy or liver transplant, may decrease mortality and complication rates. The underlying cause of PC requires careful investigation. In cases of PVT and cavernous transformation, hypercoagulability workup is advised. Cases of JAK2 point mutation and myeloproliferative dysfunction leading to PC and associated advanced cirrhosis have been noted.