Pancreato-hepato-biliary disease Pancreatic involvement commonly manifests as autoimmune pancreatitis (type 1, IgG4-related) and may take the form of An obstructive pancreatic mass, with painless jaundice and diffuse pancreatic enlargement Acute pancreatitis with abdominal pain and nausea Smoldering and insidious chronic pancreatitis with pancreatic atrophy, exocrine pancreatic insufficiency, and / or overt diabetes mellitus IgG4-related sclerosing cholangitis can occur, usually in patients who also have autoimmune pancreatitis.