Fig. 2: An ERCP image (injection of pancreatic duct) shows irregular narrowing of the pancreatic duct (arrowheads).
- Relatively new, rare disease first described in 1995 by Yoshida et al.
- Chronic pancreatitis characterized by autoimmune inflammatory process (lymphocytic infiltrates) with associated fibrosis of pancreas
- Associated with immunologic abnormalities: hypergammaglobulinemia, elevated serum IgG4 levels and autoantibodies against carbonic anhydrase and lactoferrin
- Pathology shows diffusely indurated and firm pancreas, with periductal lymphocytic and plasma cell infiltrates
- Involvement of the gallbladder, bile ducts, kidney, lung and salivary glands has been described
- 5-6% of all patients with chronic pancreatitis
- Men > women, most are > 50 years
- Mostly associated with other autoimmune disease e.g. rheumatoid arthritis, Sjogren's syndrome, inflammatory bowel disease
- Responsive to steroid
- On CT, diffuse pancreatic enlargement, enhanced peripheral rim of hypoattenuation "halo", low attenuation "mass" in pancreatic head, homogeneous attenuation and loss of lobularity
- Minimal peripancreatic fat stranding
- Involution of pancreatic tail in long-standing disease
- On ERCP, focal, diffuse or segmental pancreatic ductal narrowing, disappearance of right-angled branches
Finkelberg DL, Sahani D, Deshpande V, et al. Autoimmune pancreatitis. N Eng J Med 2006;355:2670-2676.