Validity of the management strategy for intraductal papillary mucinous neoplasm advocated by the international consensus guidelines 2012: a retrospective review

Yusuke Watanabe, Kazuyoshi Nishihara, Yusuke Niina, Yuji Abe, Takao Amaike, Shin Kibe, Yusuke Mizuuchi, Daisuke Kakihara, Minoru Ono, Sadafumi Tamiya, Satoshi Toyoshima, Toru Nakano, Shoshu Mitsuyama

The aim of this study was to investigate the validity of the management strategy for intraductal papillary mucinous neoplasms (IPMNs) advocated by the international consensus guidelines 2012 (ICG2012). The medical records of 49 patients who underwent pancreatectomy for IPMN were retrospectively reviewed. According to preoperative imaging, 10 patients (20 %) had main-duct IPMNs, 20 (41 %) had mixed IPMNs, and 19 (39 %) had branch-duct IPMNs, with malignancy frequencies of 80, 15, and 37 %, respectively. Twenty-seven patients had high-risk stigmata and 21 had worrisome features, with malignancy frequencies of 59 and 10 %, respectively. The sensitivity, specificity, and positive and negative predictive values of high-risk stigmata for malignancy were 88, 65, 59, and 91 %, respectively. Lesions were malignant in 88 % of patients with an enhanced solid component, which was significantly correlated with the prevalence of malignancy (P < 0.01). However, of the 10 patients who underwent pancreatectomy solely due to a main pancreatic dilation of ≥10 mm, 9 (90 %) had benign IPMNs. Many mixed IPMNs defined according to ICG2012 are benign. Although the management strategy advocated by ICG2012 has been improved relative to the Sendai criteria, the different high-risk stigmata carry unequal weights. Consequently, ICG2012 remains suboptimal for predicting malignant IPMN.