The Carcinoembryonic Antigen Level in Pancreatic Juice and Mural Nodule Size Are Predictors of Malignancy for Branch Duct Type Intraductal Papillary Mucinous Neoplasms of the Pancreas

Objective: Identification of predictors of malignancy for branch duct type intraductal papillary mucinous neoplasms (IPMN). Background: Main duct type IPMN has been recommended for resection. However, the indications for resection of the branch duct type IPMN have been controversial. Methods: We retrospectively analyzed the clinicopathological factors of 134 patients undergoing resection for branch duct type IPMN, excluding main duct type IPMN, to identify predictors of the malignant behavior of this neoplasm. The cutoff values of tumor size, main pancreatic duct (MPD) size, mural nodule size, and carcinoembryonic antigen (CEA) level in the pancreatic juice obtained during preoperative endoscopic retrograde pancreatography (ERP) were analyzed using receiver-operator characteristic curves. Results: We found 7 significant predictors for malignancy in the branch duct type IPMN in a univariate analysis; jaundice, tumor occupying the pancreatic head, MPD size >5 mm, mural nodule size >5 mm, serum carbohydrate antigen (CA) 19-9 level, positive cytology in the pancreatic juice, and CEA level in the pancreatic juice >30 ng/mL. In a multivariate analysis, a mural nodule size >5 mm and a CEA level in the pancreatic juice >30 ng/mL were independent factors associated with malignancy. The positive predictive value of a mural nodule size >5 mm and a CEA level in the pancreatic juice >30 ng/mL was 100%, and the negative predictive value was 96.3%. Conclusions: We identified 2 useful predictive factors for malignancy in branch duct type IPMN; a mural nodule size >5 mm and a CEA level in the pancreatic juice obtained by preoperative ERP >30 ng/mL.