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

• Published in: Pancreatology : official journal of the International Association of Pancreatology (IAP) ... [et al.] Vol. 21; no. 4; pp. 755 - 762
• Main Authors: Abe, Kodai, Kitago, Minoru, Masugi, Yohei, Iwasaki, Eisuke, Yagi, Hiroshi, Abe, Yuta, Hasegawa, Yasushi, Fukuhara, Seiichiro, Hori, Shutaro, Tanaka, Masayuki, Nakano, Yutaka, Yokose, Takahiro, Shimane, Gaku, Sakamoto, Michiie, Kitagawa, Yuko
• Format: Journal Article
• Language: English
• Published: Switzerland Elsevier B.V 01.06.2021; Elsevier Limited
• Subjects: Adenocarcinoma, Mucinous - surgery; Carcinoma, Pancreatic Ductal - diagnostic imaging; Carcinoma, Pancreatic Ductal - surgery; Cysts; Gender; High-risk stigmata; Humans; IPMN; Magnetic resonance imaging; Main pancreatic duct; Medical prognosis; Metastasis; Mucin; Natural history; Pancreas; Pancreatic cancer; Pancreatic Intraductal Neoplasms - diagnostic imaging; Pancreatic Intraductal Neoplasms - surgery; Pancreatic Neoplasms - diagnostic imaging; Pancreatic Neoplasms - surgery; Pancreatitis; Pancreatobiliary subtype; Prognosis; Retrospective Studies; Risk factors; Surgery; Survival analysis; Tumors; Ultrasound; IPMN; Pancreatobiliary subtype; High-risk stigmata; Main pancreatic duct
• ISSN: 1424-3903; 1424-3911
• DOI: 10.1016/j.pan.2021.02.012

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. 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. 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). 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.