A 42 year-old man had a chief complaint of abdominal pain lasting for a few days. His medical record comprised lacrimal gland enlargement, surgery, and PSL. He also had lacrimal gland enlargement on admission. Blood test revealed elevated IgG and IgG4 levels of 2,119 and 1,060 mg/dl, respectively. Other parameters were normal. Abdominal computed tomography revealed a 20-mm tumor within the pancreatic body, and endoscopic retrograde cholangiopancreatography revealed irregular narrowing of the main pancreatic duct. Our diagnosis was autoimmune pancreatitis (AIP) based on Clinical Diagnostic Criteria for Autoimmune Pancreatitis 2011. Corticosteroid, the standard AIP therapy, was administered to the patient, resulting in IgG4 elevation and gland enlargement improved. AIP is characterized by enlarged pancreas and irregular narrowing of the main pancreatic duct. The condition is often complicated by IgG4-related sclerosing cholangitis, dacryoadenitis, and other diseases. Many issues related to the indications of bile duct drainage and use of immunomodulating drugs remain unaddressed for better AIP diagnoses. Whole-body evaluation is vital when an IgG4-related disease is suspected.
