Split sample comparison of ThinPrep and conventional smears in endoscopic retrograde cholangiopancreatography-guided pancreatic fine-needle aspirations

Fine-needle aspiration (FNA) of pancreatic lesions is a common procedure to establish a tissue diagnosis before chemotherapy or surgery. In this study, the authors attempt to compare the diagnostic value of the ThinPrep (TP) method with conventional smears (CSs) in samples obtained by endoscopic retrograde cholangiopancreatography (ERCP)-guided pancreatic FNAs. Material obtained, prospectively, from ERCP-guided pancreatic FNAs was split to prepare CSs (2-5 slides) first, the remainder being rinsed in PreservCyte, and in the laboratory, 1 TP slide was prepared. The diagnostic categories of unsatisfactory, benign, reactive, suspicious for malignancy, and malignant were compared. Fifty-one pancreatic FNAs prepared by split sample method yielded the following results: TP yielded unsatisfactory, 6 cases; benign, 3 cases; reactive, 5 cases; suspicious for malignancy, 11 cases; and malignant, 26 cases; in contrast, CS yielded unsatisfactory, 13 cases; benign, 4 cases; reactive, 3 cases; suspicious for malignancy, 13 cases; and malignant, 18 cases. Histological follow-up was available in 21 cases (reactive, 8 cases; suspicious for malignancy, 1 case, and malignant, 12 cases). The foregoing data indicate a higher sensitivity in detection of pancreatic adenocarcinoma by the TP method (TP, 91% vs. 58% CS) with equivalent specificity (100%). In addition, TP provides better preservation and cytological detail.