S2491 Small Duct Primary Sclerosing Cholangitis: An Atypical Presentation

Abstract

INTRODUCTION: Primary sclerosing cholangitis (PSC) is a chronic progressive disease of the liver and biliary tract causing cholestasis, fibrosis, and strictures in intra and extrahepatic bile ducts. Patients are often asymptomatic, but as the disease progress, complications occur and include: recurrent cholangitis, portal hypertension, cirrhosis of the biliary tract, end-stage liver disease, and hepatobiliary malignancies, namely cholangiocarcinoma. Within the entity of PSC, there are two distinct variants: small duct PSC and large duct PSC. Here we present a case of small duct PSC presenting atypically with chronic portal vein thrombosis and a hilar mass. CASE DESCRIPTION/METHODS: 36- year old Pakistani man presented with right upper quadrant abdominal pain, jaundice, and fever. He reported a history of chronic abdominal pain and recurrent jaundice, as well as chronic portal vein thrombosis (PVT) since childhood. The patient was recently hospitalized in another institute for the same complaint for which he had a Computerized tomography (CT) of the abdomen that revealed marked splenomegaly together with evidence of portal vein occlusion with cavernous transformation as well as Intrahepatic biliary ductal dilation with a transition in the common hepatic duct and a hilar mass. The patient underwent endoscopic retrograde cholangiography (ERC) with biopsies obtained through cholangioscopy that were unremarkable. Liver biopsy showed findings consistent with primary sclerosing cholangitis with acute cholangitis and changes secondary to portal vein thrombosis. DISCUSSION: Primary sclerosing cholangitis is a chronic, incurable disease in which the liver and biliary tract become fibrosed, and strictures form in the intra and extrahepatic biliary ducts causing obstruction, portal hypertension, and eventual liver cirrhosis necessitating a liver transplant. MRC is the most frequently used diagnostic tool due to its high specificity and sensitivity. Although ERC is more sensitive, there are added risks and complications (i.e., pancreatitis and bacterial cholangitis) with this technique. When ERC is performed, findings typically include multifocal short annular strictures, which create a "beaded" pattern. Although most patients are shown to have intra and extrahepatic bile duct involvement, a small subset presents with only intra or extrahepatic bile duct involvement. Only a few small duct PSC cases were reported in the literature, and it rarely presents with an inflammatory mass as well as PVT, as in our case.Figure 1.: Portal fibrosis with mild to focal moderate ductular reaction, accompanied by neutrophils.Figure 2.: A Coronal contrast-enhanced CT image through the abdomen shows intrahepatic beading (red arrow) with intervening sites of alternating strictures, mildly dilated, and normal ducts. There is compensatory hypertrophy of the right lobe and caudate lobe of the liver (green arrows).Figure 3.: A Coronal MRCP Image through the liver shows multiple multifocal diffuse intrahepatic and extrahepatic strictures (red arrows) and severely dilated intrahepatic ducts (blue arrows), with a branching-tree appearance. There is extrahepatic beading with intervening sites of a normal, narrow stricture (long red arrow), and mildly dilated extrahepatic ducts (yellow arrow).