**1. Introduction**

Autoimmune pancreatitis (AIP) is an emerging disease, recognized with an increasing frequency in the whole world. Autoimmune factors have been known since long time to participate in the etiology of some cases of chronic pancreatitis [1]; however, their importance was somewhat marginal, no more than 3–5% of the patients of chronic pancreatitis [2, 3]. In addition, pancreatic involvement is relatively rare in the major autoimmune diseases: while described, chronic pancreatitis is only exceptionally found in lupus erythematosus [4] and Sjögren's syndrome [5, 6]. Conversely, AIP while described before [7, 8] was identified as an independent entity only in 1995 [9], and it is associated with specific IgG4-related autoimmune disease (type 1) and with inflammatory bowel disease (type 2). Their histology is characteristic and quite different when compared to pancreatic involvement in SLE or Sjögren's syndrome. This fact is very similar to the case of the liver, hepatitis associated with lupus and autoimmune hepatitis being also the two distinct diseases [10].
