Accuracy of endoscopic ultrasound‐guided fine needle aspiration cytology on the differentiation of malignant and benign pancreatic cystic lesions: A single‐center experience

Abstract

The aim was to compare the use of endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) in cytology and the biochemical analysis of cyst fluid, together with the size of the lesion in the differentiation between benign and malignant pancreatic cystic lesions. Data of patients who underwent EUS-FNA for pancreatic cystic lesions in our center from January 2006 to October 2010 were retrospectively analyzed. The diagnostic accuracy of EUS-FNA was determined. Of the 56 patients, 37 (66.1%) had evaluable cytology for diagnosis and sufficient cyst fluid was available for biochemical analysis in 58.9% (33/56) of the patients. The sensitivity, specificity, positive predictive value and negative predictive value of EUS-FNA for detecting malignancy were 63%, 100%, 100% and 85%, respectively. EUS-FNA was the most accurate diagnostic method for differentiating malignant and benign pancreatic cystic lesions (88%). Cyst fluid carcinoembryonic antigen (CEA) > 365 ng/mL had a sensitivity of 100% for the detection of malignant cystic lesions. Although the rate of insufficient cyst fluid aspiration is high, the combination of cytological evaluation and CEA analysis of cyst fluid obtained by EUS-FNA is accurate in differentiating malignant cystic lesions from benign ones. Safe techniques are essential to improve the yield of cyst fluid aspiration by EUS.