BACKGROUND/AIMS: Pancreatic cystic neoplasms represent a heterogeneous group of tumors with varied malignant potential. The aim of this prospective study was to evaluate EUS, EUS-FNA and cyst fluid analysis in distinguishing serous cystadenomas (SCA) and mucinous cystic neoplasms (MCN). METHODOLOGY: Twelve patients with SCA (4 men, 8 women, mean age 58), 16 with MCN (3 men, 13 women, mean age 53) and 10 pancreatic non-tumorous cysts as controls (1 man, 9 women, mean age 43) were investigated by EUS-FNA from January 2003 to February 2006. Cyst fluid evaluation was done for cytology, amylase, CEA, CA 19-9, CA 72-4 and CA 15-3 (RIA). The final diagnosis was based on surgery & histology (14 patients) and/or follow-up after EUS-FNA (mean 15 months). RESULTS: In the MCN-group 13 mucinous cystadenomas, 2 cystadenocarcinomas and 1 malignant IPMT were found. EUS-FNA results: cytology (including staining for mucin) was diagnostic in 2/12 SCA (17%), 10/16 MCN (63%) and negative in all controls. Fluid CEA in MCN-group (mean 9487, 95%CI 0-23637) was significantly higher compared both with SCA-group (mean 22, 95%CI 0-54, p<0.001) and controls (mean 4, 95%CI 0.5-8, p<0.001). Similar results were found in fluid CA72-4 and fluid CA19-9. Accuracy of EUS-FNA with final diagnosis was 93%. CONCLUSIONS: EUS-FNA with cyst fluid CEA, CA72-4, CA19-9 and cytology are useful tools in differentiating SCA, MCN and non-tumorous cysts.

2nd Department of Medicine Charles University in Praha Faculty of Medicine at Hradec Kralove University Teaching Hospital Hradec Kralove Czech Republic