1368 Hilar Inflammation Mimicking a Klatskin Tumor

Abstract

INTRODUCTION: Hilar cholangiocarcinomas or Klatskin tumors (KT) pose significant diagnostic challenges; 15% of resections for KT prove to be non-malignant. Inflammatory, infectious, and other etiologies mimic radiological features of KT. A high index of suspicion is needed to avoid hepatic resection and associated morbidities while aggressively excluding KT. CASE DESCRIPTION/METHODS: A 64-year-old male who presented with jaundice, unintentional 50 lb weight loss, and fatigue was found to have bile duct dilation on ultrasound. A CT confirmed severe right and left hepatic duct dilatation with abrupt cutoff due to a 4 cm infiltrative hilar mass involving the right and left hepatic ducts, and extending into the common hepatic duct. Work-up for causes of jaundice (autoimmune hepatitis, hemochromatosis, alpha-1 antitrypsin deficiency, viral hepatitis, celiac sprue, autoimmune cholangiopathy) via ANA, AMA, F-actin, IgG, IgG4, HFE mutation, TIBC, ferritin, A1AT, tTG, hepatitis serologies was negative. Over 12 weeks, 3 ERCPs failed to confirm KT via biopsies, cytology, and fluorescence in situ hybridization (FISH). A severe proximal common hepatic duct stricture was found on initial ERCP, which was dilated and stented. ERCP with Spyscope showed hepatic bifurcation stricture improvement. This stricture was biopsied and again brushed, dilated and stented. A third ERCP showed further improvement in stricture and otherwise normal intra- and extra-hepatic ducts. Dilation to 8 mm was performed without further stenting. Cytology and FISH were negative for KT. Two CT guided biopsies of the mass were also negative for KT and failed to show biliary ductal thickening or clear evidence of the prior noted hilar mass. Two MRCPs, 7 months apart, showed significant improvement of right and left bile duct confluence stricturing, felt to represent fibrous tissue and scarring. DISCUSSION: Despite improvement in cross sectional imaging, advances in interventional radiologic and endoscopic modalities, differentiation between benign and malignant hilar biliary stenoses remains a major challenge. Up to 20% of hilar resection show chronic fibrosing inflammation without evidence of KT. We aggressively pursued this concern with 3 ERCPs (cytology, FISH, biopsy with Spyscope), and 2 CT guided biopsies. CT and MR showed radiologic improvement of the mass and lack of evidence of KT. Exclusion of autoimmune disease or other etiologies allowed a diagnosis of idiopathic inflammation, thus avoiding surgery.