A History of Acute Pancreatitis in Intraductal Papillary Mucinous Neoplasms of the Pancreas Is a Potential Predictive Factor for Malignant Papillary Subtype

Background/Aims: There are several reports regarding intraductal papillary mucinous neoplasms (IPMNs) detected after the occurrence of acute pancreatitis. Although the presence of symptoms is regarded as a factor for predicting malignant IPMNs, there have been few reports demonstrating whether a history of acute pancreatitis is a predictor of malignancy. The aim of this study was to evaluate the relationship between a history of acute pancreatitis and clinicopathological features of IPMNs including the papillary subtype. Methods: The data of 150 IPMNs resected between 1990 and 2009 were retrospectively reviewed. They were classified into IPMNs with or without history of acute pancreatitis, and then the clinicopathological features were compared between the 2 groups. Results: Nineteen (13%) of the 150 patients had a history of acute pancreatitis. Nine of them had repeated episodes of pancreatitis; however, severe pancreatitis was uncommon. The diameter of the main pancreatic duct of the pancreatitis group was significantly larger than that of the nonpancreatitis group (p = 0.04). The pancreatitis group had a significantly higher frequency of carcinoma derived from IPMNs than the nonpancreatitis group (p = 0.03). The incidence of intestinal-type IPMNs in the pancreatitis group was significantly higher than that in the nonpancreatitis group (p < 0.001). Conclusion: Acute pancreatitis associated with IPMNs could predict malignant intestinal-type tumor.