1424 Follicular Cholangitis Presenting as Cholangiocarcinoma in a Patient With Serologic Evidence of Autoimmune Disease

Abstract

INTRODUCTION: Follicular cholangitis is a rare sclerosing cholangitis of the biliary hilum that is difficult to distinguish from primary sclerosing cholangitis, immunoglobulin G4-related sclerosing cholangitis, and most imperatively, hilar cholangiocarcinoma. Pathological findings include fibrotic thickening of bile duct walls containing lymph follicles with germinal center formation. While autoimmune evaluations have previously been negative, we herein report the first case of follicular cholangitis found in the pretense of autoimmune hepatitis. CASE DESCRIPTION/METHODS: A 40-year-old female presented following a 2-month history of pruritis, fatigue, and elevation of hepatobiliary enzymes (AST 113 U/L, ALT132 U/L, ALP 499 U/L). Medical history was significant for cholestasis of pregnancy 10 years ago. Laboratory evaluation was positive for an ANA (1:160), an atypical pANCA (1:320), and an elevated F-actin (101 units) while negative for anti-mitochondrial antibody. Serum IgG levels were normal (1250 mg/dl; IgG4 subclass <1). IgM level was elevated at 350 mg/dl. Liver biopsy showed dense portal lymphatic inflammation, including focal germinal center formation as well as paucity of bile ducts without florid ductal lesion or fibrosis. Initial treatment with glucocorticoids, azathioprine and ursodiol did not improve symptoms or liver chemistries. ERCP revealed a tight stricture with direct visualization (spyglass) of a biliary lesion in the distal third of the common bile duct (CBD). Cytology from the stricture returned atypical cells suspicious for adenocarcinoma. Bile duct biopsy revealed severe chronic inflammation and few atypical glands. IgG4 immunostaining was negative. She underwent pancreaticoduodenectomy due to concern for cholangiocarcinoma. Macroscopically, the CBD mucosa was diffusely granular and without mass lesions. Microscopically; bile duct fibrosis, lymphoid hyperplasia with prominent germinal centers, and rare IgG4-positive cells were consistent with severe follicular cholangitis. DISCUSSION: Unique to this case is the serological backdrop and histologic findings of autoimmune disease. Whereas previous cases have been strictly ANA negative, there appears to be an unexplored continuum of disease as evidenced by cases of follicular bronchiolitis which have been associated with autoimmune disease and have similar immunohistologic findings. Although the etiology remains unclear, the existence of an autoimmune association raises important considerations for medical therapies.