S1407 A Rare Case of Pancreaticobiliary IgG4-Related Disease and Eosinophilic Granulomatosis With Polyangiitis (Churg-Strauss Syndrome)

Abstract

INTRODUCTION: IgG4-Related Disease (IgG4-RD) is a rare but increasingly recognized condition. It can manifest as pancreatitis and sclerosing cholangitis. Eosinophilic granulomatosis with polyangiitis (EGPA) may increase IgG4 levels but is not associated with IgG4-RD. CASE DESCRIPTION/METHODS: A 42 year old white male with longstanding EGPA on chronic prednisone had progressive malaise, sinopulmonary symptoms, and brief bouts of abdominal pain. He was admitted for an EGPA flare and abnormal liver enzymes. His exam was benign except for RUQ tenderness. Work-up revealed AST 280 U/L, ALT 330 U/L, Alkaline Phosphatase 727 U/L, bilirubin 1.6 mg/dL, ESR 82 mm/hr, and 1220 eosinophils/microL. Autoimmune, viral hepatitis, and infectious workup was negative. Chest x-ray was normal. Ultrasound showed cholelithiasis without cholecystitis or biliary dilation. MRCP showed non-visualization of a 2 cm segment in the common bile duct (CBD), and a 2.1 cm pancreatic tail cyst, prompting EUS/ERCP. Initial EUS was notable for diffuse thickening of the cystic and common bile duct, and intra- and extrahepatic bile duct dilatation and stricturing with a dominant 2 cm CBD stricture without associated mass. Following sphincterotomy, the CBD was brushed and ampulla biopsied (both benign), and CBD and pancreatic duct stented. IgG4 returned 1658 mg/dL (17x normal), and liver enzymes only mildly improved. Follow-up EUS/ERCP showed the 2.2 cm pancreatic tail cyst adjacent to a 21 × 19 mm pancreatic tail mass. Cyst aspirate was consistent with a pseudocyst. Fine needle biopsies of the pancreatic mass showed lymphocytic invasion, fibrosis and sclerosis, consistent with IgG4-RD. Cholangioscopy with Spybite sampling of the CBD stricture showed non-specific inflammatory changes. A percutaneous liver biopsy noted only hepatic steatosis. His sinopulmonary symptoms remained uncontrolled and liver enzymes remained elevated. Rituximab infusions were initiated for both EGPA and IgG4-RD. He had symptom resolution and his liver associated enzymes returned to normal. DISCUSSION: This case demonstrates IgG4-RD with pancreaticobiliary disease in a patient on chronic steroids for EGPA. Bile duct, pancreatic, and liver biopsies all lacked features of EGPA. Pancreatitis and cholangitis are not associated with EGPA. Thus, it is likely the patient had two distinct and rare processes. His chronic steroid treatment for EGPA may have masked longstanding IgG4-RD. Rituximab was shown to be an effective second-line treatment modality for both conditions.Figure 1.: EUS - Significant common bile duct wall thickening at the level of the common bile duct stricture.Figure 2.: ERCP - Areas of dilatation and stricturing/narrowing involving the intra- and extrahepatic bile ducts consistent with cholangitis. A 2cm dominant stricture is noted in the common bile duct.Figure 3.: EUS - A 21 mm × 19 mm distal body/tail mass which underwent fine needle biopsy. Biopsies returned with features of lymphocytic invasion, fibrosis, and sclerosis consistent with autoimmune pancreatitis (IgG4-RD).