Differentiating autoimmune pancreatitis from pancreatic cancer.

Differential diagnosis between autoimmune pancreatitis (AIP) and pancreatic cancer can be very difficult. The main clinical symptoms in patients with autoimmune pancreatitis are jaundice, weight loss, abdominal pain and new onset of diabetes mellitus. Unfortunately, the same symptoms could be observed in patients with pancreatic carcinoma too. Imaging methods as computed tomography (CT) scan, magnetic resonance imaging (MRI) and endosonography (EUS); together with serological examination (IgG4 and Ca 19-9) play the important role in differentiation autoimmune pancreatitis from pancreatic cancer. Extrapancreatic findings are distinctive in patients with autoimmune pancreatitis. In some cases the pancreatic biopsy is indicated, mainly in patients with focal or multifocal form of autoimmune pancreatitis. Response to steroids (decreased pancreatic or extrapancreatic lesion or damage) is distinctive to AIP. In clinical practice, CT scan seems to be the most reasonable tool for examining the patients with obstructive jaundice with or without present pancreatic mass. Stratification the patients with possible AIP versus pancreatic cancer is important. In patients with AIP it may avoid pancreatic resection, as well as incorrect steroid treatment in patients with pancreatic carcinoma.