Immunoglobulin G4 (IgG4)-related disease is a rare systemic diseases. A 67-year-old male presented at our institution with mild upper abdominal pain and jaundice for 20 d. Laboratory results revealed high levels of IgG4 (15.4 g/L, range: 0.08-1.4 g/L). Computed tomography (CT) showed significant enlargement of the entire pancreas and a capsule-like low-density rim surrounding the whole pancreas. Positron emission tomography/CT revealed increased uneven metabolism of the entire pancreas. Both magnetic resonance cholangiopancreatography and endoscopic retrograde cholangiopancreatography showed stenosis of the distal common bile duct and proximal main pancreatic duct, and dilation of the proximal common bile duct and extra- and intra-hepatic bile ducts. He was diagnosed with IgG4-related autoimmune pancreatitis. The patient was treated with prednisone for 14 mo. The patient responded well to prednisone but upon cessation of the corticosteroid developed enlargement of the submandibular gland. The patient's serum IgG4 was elevated at 23.9 g/L. It is important to maintain treatment, so the patient was again treated with prednisone and had a good response. Follow-up of IgG4-related disease is thus necessary.
Keywords: Autoimmune pancreatitis; Immunoglobulin G4; Immunoglobulin G4-related disease; Sialadenitis.