A study in the July issue of the American Journal of Roentgenology finds that the presence of atypical imaging features diminishes the diagnostic accuracy of MDCT in differentiating autoimmune pancreatitis, pancreatic ductal adenocarcinoma and acute interstitial pancreatitis in a significant number of cases.

"We found no significant difference in the incidence of focal pancreatic involvement, vascular involvement or peripancreatic lymphadenopathy between autoimmune pancreatitis and pancreatic ductal adenocarcinoma, even though these imaging features are usually considered to be pathognomonic for malignancy," said lead researcher Stephanie Lee-Felker of the David Geffen School of Medicine at UCLA. "Differentiating autoimmune pancreatitis from pancreatic ductal adenocarcinoma can be particularly difficult."

The researchers recommend that a high index of suspicion for autoimmune pancreatitis be maintained whenever a pancreatic abnormality is encountered. Radiologists can play an important role in prompting further diagnostic workup for accurate diagnosis of autoimmune pancreatitis by suggesting correlation with serum immunoglobulin 4 level and tissue sampling, potentially preventing unnecessary surgery.

Study: Use of MDCT to Differentiate Autoimmune Pancreatitis From Ductal Adenocarcinoma and Interstitial Pancreatitis, Stephanie A. Lee-Felker, Ely R. Felker, Barbara Kadell, James Farrell, Steven S. Raman, James Sayre and David S. Lu, American Journal of Roentgenology, published July 2015.