Accuracy of 2012 International Consensus Guidelines for the prediction of malignancy of branch-duct intraductal papillary mucinous neoplasms of the pancreas

Abstract

Objective: To determine accuracy of 2012 International Consensus Guidelines (ICG) predicting malignancy in a surgical cohort of branch-duct intraductal papillary mucinous neoplasms (BD-IPMN). Methods: This study included all consecutive patients with final pathological diagnosis of pure BD-IPMN resected between 2006 and 2014 at Beaujon Hospital. Neoplasms were classified as malignant in presence of high-grade dysplasia (HGD) or invasive carcinoma. Medical, pathological, and radiological data were retrospectively recorded. Results: One hundred and twenty patients (65 males, mean age: 57.9 ± 10.8 years) were included. Malignant BD-IPMN accounted for 30% (HGD: 18%, invasive: 12%). Thickened cyst walls (odds ratio (OR): 3.058, 95% confidence interval (CI 95%): 1.102–8.484, p = 0.032), main duct diameter 5–9 mm (OR: 3.395, CI 95%: 1.349–8.543, p = 0.007), and mural nodule (OR: 3.802, CI 95%: 1.156–12.511, p = 0.028) were independently associated with malignancy in multivariate analysis. Among the 89 patients (74%) who underwent surgical resection with ICG criteria, the malignancy rate was 38%, compared with 6% in the 31 ICG-negative group. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy for malignancy of having at least one ICG criteria were 94%, 34%, 38%, 94%, and 53%, respectively. Patients with malignant tumors had more ICG criteria than those with benign lesions (2.06 ± 0.98 vs. 0.99 ± 0.95, p < 0.001). Conclusions: 2012 ICG criteria are useful to manage BD-IPMN permitting not to miss a malignant form (NPV of 94%), but frequently point out unnecessary surgery (PPV of 38%). Malignancy rate increases with the number of ICG criteria. In patients with only one criterion, additional criteria would be necessary.