Autoimmune pancreatitis mimicking pancreatic tumor

Autoimmune pancreatitis (AIP) is a rare disease of unknown pathomechanism. AIP belongs to the IgG4-related disease family and responds well to steroids, although the relapse rate can reach up to 20-30%. Differentiation of AIP from the more common pancreatic cancer can be very challenging. About 20% of autoimmune pancreatitis is diagnosed postoperatively during final histological examination. While each of diagnostic investigations provide some additional information towards definitive diagnosis, the question still remains whether it is possible to prevent unnecessary pancreatic resection. We demonstrate the differential diagnostic opportunities when we present our case as well as discuss the literature data of this condition. In conclusion, we think that in case of a focal pancreatic lesion AIP should always be considered.