Diagnostic Accuracy of Endoscopic Ultrasound-Guided Fine Needle Aspiration Cytology of Pancreatic Lesions

Background: Endoscopic ultrasound-guided fine needle aspiration cytology (EUS-FNAC) is currently the most commonly used procedure for obtaining cytologic specimens of the pancreas. It is accurate, minimally invasive, safe and cost-effective. However, there is discrepancy between cytological and surgical diagnoses. This study was aimed at evaluating the diagnostic accuracy of EUS-FNAC of the pancreas. Methods: We performed a retrospective review of 191 cases of pancreatic lesions initially diagnosed by EUS-FNAC with subsequent histological diagnosis between 2010 and 2012 in the Department of Pathology, Seoul National University Hospital. Cytologic and surgical diagnoses were categorized into five groups: negative, benign, atypical, malignant, and insufficient for diagnosis. Subsequently, 167 cases with satisfactory yield in both surgical and cytology specimens were statistically analyzed to determine correlations with diagnosis. Results: In comparison to surgical diagnoses, cytologic diagnoses were true-positive in 103 cases (61.7%), true-negative in 28 cases (16.8%), false-positive in 9 cases (5.4%), and false-negative in 27 cases (16.1%). The diagnostic accuracy was 78.4%, sensitivity was 79.2%, and specificity was 75.7%. The positive predictive value was 92.0%, and negative predictive value was 50.9%. Conclusions: EUS-FNAC has high accuracy, sensitivity, specificity and positive predictive value. Overcoming the limitations of EUS-FNAC will make it a useful and reliable diagnostic tool for accurate evaluation of pancreatic lesions.