Intraductal papillary mucinous tumor (IPMT) of the pancreas is a spectrum of conditions ranging from benign to malignant. It is known that the biologic behavior of IPMT is slower and less aggressive than that of pancreatic ductal carcinoma. We report a case of IPMT of pancreas resected 5 years after diagnosis. The carcinoma remained localized without evident stromal invasion or lymph node metastasis with the background of adenoma, suggesting a adenomacarcinoma sequence. This is a case report that may be helpful to study the natural history of IPMT, particularly slow progression of IPMT.