Prediction of malignancy with endoscopic ultrasonography in patients with branch duct-type intraductal papillary mucinous neoplasm.

Objective: We evaluated the accuracy of a new endoscopic ultrasonography (EUS) scoring system to predict malignancy in branch duct-type intraductal papillary mucinous neoplasms (BD-IPMNs).

Methods: We performed a retrospective multicenter study of patients who underwent EUS within 3 months before surgery and were diagnosed as having BD-IPMNs by postoperative pathologies at 8 hospitals in Korea from August 2002 to December 2011. To predict the malignancy, we applied the EUS scoring system consisting of pancreatic cyst size, height of mural nodules, main duct dilatation, septal thickening, and patulous orifice. We evaluated the diagnostic accuracy of the new EUS scoring system and compared it with previous individual risk factors.

Results: Eighty-four patients (male-to-female ratio, 55:29; mean [SD] age, 64.7 [7.1] years) had 68 benign BD-IPMNs and 16 malignant intraductal papillary mucinous neoplasms. The EUS scoring system showed 75.0% sensitivity and 94.1% specificity at 7 points. This system (area under the curve, 0.939; 95% confidence interval, 0.884-0.994) resulted in a more accurate prediction than the previous known other factors including Sendai criteria, dilatation of ducts, size of the cyst, and presence of septal thickening and mural nodules.

Conclusions: The EUS scoring system predicted BD-IPMN malignancy more accurately than the Sendai criteria and individual risk factors.