Endoscopic ultrasound-guided fine-needle aspiration of solid pancreatic masses with rapid on-site cytological evaluation by endosonographers without attendance of cytopathologists

Background: Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) with rapid on-site evaluation (ROSE) has been reported to provide a more accurate diagnosis than EUS-FNA without such evaluation. However, even endosonographers can evaluate ROSE regarding sample adequacy. The aim of this study was to evaluate the diagnostic accuracy of EUS-FNA with ROSE by endosonographers compared to ROSE by cytopathologists in patients with solid pancreatic masses. Methods: Between September 2001 and October 2005, of the 73 EUS-FNA procedures with the final diagnoses, 38 procedures after the introduction of ROSE by endosonographers (September 2001-September 2003, period 1), and 35 procedures after the introduction of ROSE by cytopathologists (October 2003-October 2005, period 2) were included. The specimens were stained with Diff-Quik stain and assessed. When the on-site assessors (endosonographers or cytopathologists) indicated that the amounts of cell samples were adequate, the procedure was stopped. Results: Results are presented with 95% confidence limits. The average numbers of needle passes were 4.0± 1.6 and 3.4± 1.5 in periods 1 and 2, respectively (P = 0.06). The specimen collection rates were 97.4 and 97.1% in periods 1 and 2, respectively (P = 0.51). Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy for malignancy and benign were 92.9, 100, 100, 83.3, and 94.7%, respectively, in period 1, and 93.1, 100, 100, 75.0, and 94.3%, respectively, in period 2 (P = 0.97, P= 1.0, P = 1.0, P = 0.65, P= 0.93, respectively). No complications were seen. Conclusions: For accurate diagnosis, ROSE should be performed during EUS-FNA by the endosonographer, if no cytopathologist is available.