Diagnostic Accuracy of Endoscopic Ultrasound-Guided Fine-Needle Aspiration Cytology, Carcinoembryonic Antigen, and Amylase in Intraductal Papillary Mucinous Neoplasm

Objectives The aim of this study was to determine the accuracy of cytology, carcinoembryonic antigen (CEA), and amylase levels in the preoperative diagnosis of intraductal papillary mucinous neoplasms (IPMNs). Methods An international registry was started in 2005 and included patients with clinically suspected IPMNs. Those who underwent surgery and had preoperative endoscopic ultrasonography fine-needle aspiration were selected for the study. Results One hundred eighty patients were included. Cytological analysis for neoplastic cells in IPMNs showed high specificity (87.8%) but low sensitivity (39.4%). The median CEA level was 525.5 ng/mL (n = 78) in IPMNs versus 9.7 ng/mL in nonmucinous cysts (n = 6), showing an area under the receiver operating characteristic curve (AUC) of 0.87. The optimal cutoff CEA value for distinguishing IPMN from nonmucinous cysts was 129 ng/mL. At this level, the sensitivity was 76.9%, and specificity was 83.3%, yielding a positive predictive value of 95.9% and a negative predictive value of 41.9%. Carcinoembryonic antigen was a poor predictor of neoplasia in IPMNs (AUC = 0.55). Amylase did not distinguish IPMNs from mucinous cystadenomas (MCAs) (median, 3759 U/L [n = 28 IPMNs] and 497 U/L [n = 3 MCAs], AUC = 0.65). Conclusions Cytology has a limited role because of its lack of sensitivity. Carcinoembryonic antigen modestly differentiated between mucinous and nonmucinous lesions. Amylase did not distinguish IPMNs versus MCAs.