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. 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. 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. The history of resection of extrapancreatic malignancies should be considered during the follow-up of BD-IPMN.

中文翻译：

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胰外恶性肿瘤手术后胰腺分支管型导管内乳头状粘液性肿瘤（BD-IPMN）的进展

胰腺分支管型导管内乳头状粘液性肿瘤（BD-IPMN）的自然史仍不清楚。这项回顾性研究旨在确定 BD-IPMN 的形态变化，并关注胰外恶性肿瘤的手术切除史。这项研究纳入了 2001 年 1 月至 2019 年 12 月在大阪医学院进行的 427 名 BD-IPMN 受试者；共纳入 134 名患者。通过单变量和多变量分析评估基于形态变化的 BD-IPMN 进展的预测因素。此外，还研究了随访期间出现进展性病变的 BD-IPMN 的临床特征。平均随访时间为35.8个月（范围为12.1至157个月）。6 名受试者（4.5%）出现疾病进展。其中 2 例（1.5%）发现了 IPMN 相关的浸润性癌。多变量分析表明，胰外恶性肿瘤的手术切除是 BD-IPMN 进展的重要预测因子。BD-IPMN 随访期间应考虑胰外恶性肿瘤切除史。