Comparison of the international consensus guidelines for predicting malignancy in intraductal papillary mucinous neoplasms.

BACKGROUND: This study sought to evaluate the predictors of malignancy in the 2012 international consensus guidelines for intraductal papillary mucinous neoplasms (IPMNs) and validate their diagnostic value relative to the 2006 guidelines.
METHODS: Between 2002 and 2014, 177 consecutive patients who underwent curative resection of IPMN were reviewed. Based on the 2012 guidelines, high-risk stigmata (mural nodule with enhancement, main pancreatic duct [MPD] ≥ 10 mm, and obstructive jaundice) and worrisome features (cyst size ≥ 30 mm, thickened cyst wall, mural nodule without enhancement, MPD 5-9 mm, an abrupt change in MPD diameter, and lymphadenopathy) were assessed, and predictive and diagnostic values were analyzed statistically.
RESULTS: Multivariate analysis identified obstructive jaundice (odds ratio [OR], 23.9; P < .0001), abrupt change in MPD diameter (OR, 3.01; P = .017) and lymphadenopathy (OR, 5.84; P = .027) as independent predictive factors, with an accuracy of 69.8, 67.4, and 66.3%, respectively. Operative intervention was indicated in 156 patients (94.0%) using the 2006 guidelines, and in 130 (78.3%) using the 2012 guidelines. The accuracy of the 2006 guidelines was 35.5% compared with 44.8% for the 2012 guidelines. The area under the curve (AUC) for the 2006 and 2012 guidelines was 0.65 and 0.67, respectively; ΔAUC was 0.02, which was not statistically significant. When the worrisome features were combined with high-risk stigmata, the AUC increased to 0.79.
CONCLUSION: Obstructive jaundice, abrupt change in MPD diameter, and lymphadenopathy were independent predictive factors in the 2012 guidelines with high accuracy. Using the new guidelines, the number of patients with IPMN managed with observation and the predictive accuracy increased.