Obstructive Jaundice Secondary to IgG-4 Biliary Stricture with Normal Serum IgG4 and Normal Pancreas Imaging

Abstract

Purpose: New onset obstructive jaundice in a middle aged individual is usually malignant in etiology. IgG-4 Systemic Disease (ISD) is composed predominantly of autoimmune pancreatitis and cholangitis, both of which can present with obstructive jaundice. We report a patient with obstructive jaundice and a biliary stricture secondary to ISD with normal serum IgG-4 levels and normal pancreas on radiologic studies. Methods: Case Report: 64 y/o man presented with 4 days of painless jaundice and weight loss over the preceding 2–3 months. He had no abdominal pain or back pain, denied any drug use and was on no medications. His physical examination was unremarkable except for scleral icterus. Labs included a total bilirubin 14 mg/dl (nml < 1.3) and direct of 10 mg/dl (nml < .3), AlkPhos of 470 IU/L (nml < 126) and ALT- 209 IU/L (nml < 56), AST- 122 IU/L (nml < 35), CA 19-9- 50 u/ml (nml < 37). RUQ US showed a dilated proximal common bile duct, without cholelithiasis or cholecystitis. Abdominal CT showed a 1.1 cm CBD with biliary tree dilatation and no evidence choledocholithiasis. MRCP demonstrated that in the mid CBD ∼4 cm proximal to the ampulla an obstructing lesion with an abrupt tapering of the CBD at the level of obstruction. The patient underwent surgical exploration for a presumed cholangiocarcinoma. At surgery, there was no evidence of metastatic disease. The gallbladder was distended and inflamed and CBD was dilated proximally and distally had thickened walls. Core biopsies of the bile ducts showed inflammatory changes and a cholecystectomy and hepatico-jejunostomy were performed. Histopathological exam showed chronic inflammatory changes with fibrosis and plasmalymphocytic infiltrate; bile duct tissue stained positive for IgG-4. Serum markers for ISD including anti- Carbonic Anhydrase and serum IgG-4 levels were within normal limits. Results: Isolated dominant bile duct strictures in the naïve patient are commonly due to malignancy. However, as in our patient, ISD mediated bile duct inflammation leading to stricture formation must now be considered. It can be isolated without associated autoimmune pancreatitis and may not have elevated serum IgG-4 levels. This diagnosis is usually made on biopsy after a surgical procedure. If diagnosis can be made pre-operatively, biliary obstruction may be treated medically with corticosteroids and possibly endocscopically and avoid surgery. Steroids are necessary for inducing remission and resolution of symptoms post biliary stenting endoscopically. Conclusion: IgG-4 cholangitis is part of the spectrum of ISD and must be considered in any patient with biliary stricture, even in the absence of pancreatic pathology and normal serum IgG-4 value.