Indication for resection and possibility of observation for intraductal papillary mucinous neoplasm with high-risk stigmata

Kodai Abe, Minoru Kitago, Yohei Masugi, Eisuke Iwasaki, Hiroshi Yagi, Yuta Abe, Yasushi Hasegawa, Seiichiro Fukuhara, Shutaro Hori, Masayuki Tanaka, Yutaka Nakano, Takahiro Yokose, Gaku Shimane, Michiie Sakamoto, Yuko Kitagawa

Research output: Contribution to journalArticlepeer-review

4 Citations (Scopus)


Background/Objectives: According to the revised international intraductal papillary mucinous neoplasm (IPMN) guidelines (2017), the indication for surgery is based on risk classification. However, some IPMNs with high-risk stigmata (HRS) can be observed for long periods without resection. Hence, we need to reconsider the risk stratification, and this study aimed to propose a novel risk stratification for HRS-IPMNs. Methods: We enrolled 328 patients diagnosed with IPMN using endoscopic ultrasound between 2012 and 2019. We compared clinicopathological features between HRS and worrisome features (WF) and evaluated outcomes of HRS-IPMN. Results: Fifty-three patients (HRS 38, WF 15) underwent resection at initial diagnosis and 275 patients were observed. Following observation for 30 months, 22 patients (17 HRS, 5 WF) underwent resection. Analysis of resected IPMNs (n = 75) revealed that HRS had dominantly pancreatobiliary mucin subtype. Pancreatobiliary-type IPMN had larger nodule sizes and lymphatic invasion and high recurrence with poor prognosis. Seventy-four patients were diagnosed with HRS, 55 underwent resection, and 19 continue to be observed. The resected group had larger nodule sizes (median 8 mm vs. 5 mm; P = 0.060), whereas the observed group had more main pancreatic duct (MPD) dilation (median 10 mm vs. 5 mm; P = 0.005). In the resected HRS group, only patients with MPD dilation ≥10 mm (n = 10) had no recurrence but had a favorable prognosis compared with those nodule size ≥5 mm (n = 45). Conclusions: Large nodule size may be associated with pancreatobiliary subtype and poor prognosis; however, patients with MPD dilation ≥10 mm with nodule size <5 mm did not require resection.

Original languageEnglish
Pages (from-to)755-762
Number of pages8
Issue number4
Publication statusPublished - 2021 Jun


  • High-risk stigmata
  • IPMN
  • Main pancreatic duct
  • Pancreatobiliary subtype

ASJC Scopus subject areas

  • Endocrinology, Diabetes and Metabolism
  • Hepatology
  • Gastroenterology


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