Progression of pancreatic branch duct-type intraductal papillary mucinous neoplasms (BD-IPMNs) after surgery for extrapancreatic malignancies

Background/aims The natural history of pancreatic branch duct-type intraductal papillary mucinous neoplasms (BD-IPMNs) is still unknown. This retrospective study aims to determine the morphological changes of BD-IPMNs with attention to the history of surgical resection for extrapancreatic malignancies. Methods and materials This study included 427 subjects with BD-IPMN at the Osaka Medical College from January 2001 to December 2019; 134 patients were included. The predictive factors for the progression of BD-IPMN based on morphological changes were evaluated by univariate as well as multivariate analyses. Furthermore, the clinical features of BD-IPMNs with progressive lesions during follow-up were investigated. Results The average interval of follow-up was 35.8 months (with a range between 12.1 and 157 months). Disease progression occurred in 6 subjects (4.5%). In two of them (1.5%), IPMN-related invasive carcinoma was found. Multivariate analysis demonstrated that surgical resection for extrapancreatic malignancies was a significant predictor of BD-IPMN progression. Conclusion The history of resection of extrapancreatic malignancies should be considered during the follow-up of BD-IPMN.