Autoimmune pancreatitis

  • No history of alcohol use or biliary stone disease
  • Immune-mediated
  • Gland infiltrated by CD4 positive lymphocytes and plasma cells
  • Serum IgG4 sometimes elevated
  • Responds to steroids
  • Focal form difficult to distinguish from malignancy
  • May be associated with other IgG4 issues: cholangitis, renal, salivary gland or lacrimal gland inflammation, lymphadenopathy


  • 3 types in imaging: diffuse, focal or multi-focal
  • Diffuse most common 70%
  • Diffuse (sausage shaped) or focal gland enlargement
  • Minimal duct dilatation
  • Delayed contrast enhancement
  • Perpancreatic hypo-attenuating rim