Endoscopic ultrasound-guided fine-needle aspiration of pancreatic cystic lesions provides inadequate material for cytology and laboratory analysis: initial results from a prospective study

Background and study aims: Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) is considered a valuable and safe technique for further investigation of pancreatic cystic lesions. In the framework of a prospective study on the accuracy of EUS-FNA we report our initial technical results regarding puncture access, sample adequacy, and complications Patients and methods: Consecutive patients with indeterminate pancreatic cystic lesions underwent EUS and EUS-FNA. Pancreatic cyst fluid was collected for cytopathological analysis and measurement of amylase, carcinoembryonic antigen (CEA), and carbohydrate antigen 19.9 (CA 19.9) levels. Main outcome parameter for this analysis was the percentage of samples adequate for cytologic and laboratory analysis. Results: Of 143 patients (median age 63 years; median cyst size 2.8 cm) who underwent EUS, FNA was performed in 128 (90 %). The various reasons for not doing FNA included large distance between transducer and cystic lesion (n = 9), cyst not seen or too small (n = 2), and evident diagnosis not requiring FNA (n = 3). FNA was not possible in four patients (technical failures). Cyst fluid sent for cytology provided adequate cellular material in 44 cases only, accounting for an intention-to-diagnose yield of 31% (44/143). Sufficient fluid for biochemical analysis was obtained in 68 cases (49 %). Complications occurred in three patients (2.4 %). Conclusions: Although EUS-guided FNA was technically feasible in the majority of patients with pancreatic cystic lesions (87 %), it was possible to obtain a classifying cytopathologic diagnosis and a chemical analysis in only a third and a half of cases, respectively.