Long-Term Follow-Up of Autoimmune Pancreatitis Immunoglobulin G4-Related Disease Diagnosed by EUS-FNA: Case Report

Context Autoimmune pancreatitis (AIP) is a recurrent, infiltrative, inflammatory disease, which is not limited to pancreatic involvement and has a multiform clinical presentation. The diagnosis is made in patients with painless obstructive jaundice secondary to an inflammatory mass involving the biliary tract, accompanied by abdominal pain, weight loss, and increased levels of carbohydrate antigen 19-9 (CA19-9), mimicking pancreatic carcinoma. Tissue procurement is considered the "gold standard" for the diagnosis of AIP. Case report We report a case of IgG4 syndrome with a significant increase in CA19-9 level, acute pancreatitis, and enlargement of the pancreatic gland mimicking pancreatic carcinoma. An accurate diagnosis was obtained by EUS-FNA, and steroid treatment avoided unnecessary surgery. Conclusions We should investigate for the presence of AIP (IgG4 syndrome) in patients, mainly men over 50 years old, who have acute or chronic pancreatitis of unknown cause and a mass in the head of the pancreas. EUS-FNA avoided unnecessary Whipple surgery and determined the best treatment for the pancreatic mass identified by imaging methods.