Comparison of cytologic preparation methods in endoscopic ultrasound-guided fine needle aspiration for diagnosis of pancreatic adenocarcinoma

Background There are few studies about the diagnostic yield of cytologic preparation method of pancreatic samples obtained by Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA). The aim of this study was to compare the accuracy of ThinPrep^® and smear method in diagnosis of pancreatic cancer. Methods A total of 125 EUS-FNA procedures were performed between July 2010 and June 2015. Patients in group I (n = 36; July 2010 to June 2014) had cytology slides prepared by consecutive allocation of samples. Patients in group II (n = 12; July 2014 to June 2015) had cytology slides prepared by alternately allocation of samples. Results There were 24 men and 24 women (median age: 67 years; range 39–84). The median size of lesions was 3.9 cm (range; 1.4–7.2 cm). The locations of the pancreatic cancer were 10 in head (20.8%), 21 in body (43.8%), and 17 in tail (35.4%). The ThinPrep^® method confirmed malignancy in 35 of 48 cases (72.9%). On the other hand, the smear method confirmed malignancy in 44 of 48 cases (91.7%). The diagnostic yield of smear method was statistically higher than liquid method (P = 0.012). Also, smear method is superior to liquid method in both consecutive and alternative allocation method. ThinPrep^® provided a correct diagnosis in one case where the smear method was incorrect. Conclusions Smear method was a superior preparation method to liquid method in diagnosis of pancreatic cancer, even if splitting method was not used and variable allocation method was used.