In the current era of personalized surgery, great efforts are being made to refine surgical indications for intraductal papillary mucinous neoplasm (IPMN). The controversial article by Hirono et al1 from Japan in this issue of JAMA Surgery addresses this topic by retrospectively reviewing 286 patients who underwent resection for IPMN, with the aim of identifying factors associated with malignancy specific to each IPMN morphological type. Among others, larger mural nodule size for all types and high carcinoembryonic antigen levels in the pancreatic juice for main duct and mixed IPMNs were found to be associated with invasive behavior. Hirono et al1 found that these factors correlated with malignancy more accurately than current, established guidelines.2,3