Intraductal papillary mucinous neoplasms of the pancreas complicated with intraductal hemorrhage, perforation, and fistula formation: CT and MR imaging findings with pathologic correlation

To correlate the CT and MR images with pathologic findings on intraductal papillary mucinous neoplasms (IPMNs) complicated with intraductal hemorrhage, perforation, and fistula. We retrospectively evaluated the CT (n = 5), MR imaging (n = 4), and pathological features of five IPMN patients complicated with intraductal hemorrhage (n = 5), perforation (n = 1), and fistula into the duodenum and jejunum (n = 1). Intraductal hemorrhage could be detected as high attenuation on non-contrast CT in two of the five cases, and as high signal intensity on fat-suppressed T1-weighted MR images in all four of the cases. Perforation and fistula could be recognized on CT images. In all IPMNs, denuded epitheliums were observed pathologically. Dissolution of the duct wall and extension of mucinous materials were seen at the area of denuded epithelium. Perforations and fistula, without evidence of cancer invasion, were recognized in the dissolved duct wall. Pathogenesis of the perforations and fistula formations appeared to be related to excessive pressure in the dilated ducts and autodigestion of enzyme-rich fluids. Complications with IPMN could be recognized on CT and fat-suppressed T1-weighted MR images. Intraductal hemorrhage might be predictive sign of perforation and fistula formation.