Autoimmune Pancreatitis Presenting as a Focal Pancreatic Mass Mimicking Pancreatic Cancer: A Case Report and Review of the Literature

Abstract

A 68-year-old female presented with a 2-week history of jaundice, generalized itching and weight loss in 2006. On physical examination, she was deeply jaundiced; however, other clinical examinations were completely unremarkable. Liver function tests (LFTs) were deranged: serum alkaline phosphatase 407 U/L (35 - 104), serum aspartate transaminase 57 U/L (0 - 31), serum alanine transaminase 184 U/L (0 - 37), and serum total bilirubin 4.3 mg/dL (0 - 1). Abdominal CT revealed a 4.8 cm 3.5 cm mass in the pancreatic head. ERCP revealed a high-grade stricture in the distal CBD. An internal biliary stent was placed in to the CBD stricture. Patients symptoms relieved after biliary stenting. Serum CA 19-9 was elevated at 1,568 U/mL (0 - 37). Due to high suspicion for pancreatic cancer, patient underwent pylorus-sparing pancreaticoduodenectomy. Histopathology was benign and showed perilobular lymphoplasmacytic infiltrate, periductal fibrosis and phlebitis that was consistent with autoimmune pancreatitis. Patient was started on oral prednisone that was eventually replaced with azathioprine. Serum IgG4 was 53 mg/dL (1 - 291) after starting steroid treatment.




J Med Cases. 2013;4(1):29-33
doi: https://doi.org/10.4021/jmc891w