Impact of rapid on-site evaluation on diagnostic accuracy of EUS-guided fine-needle aspiration of solid pancreatic lesions: experience from a single center.

BACKGROUND: The use of ROSE in EUS-FNA pancreatic lesions is still controversial in many centers. In this study, we aimed to demonstrate the contribution of ROSE to the diagnostic accuracy, as well as its assistance to the pathologist/cytopathologist. METHODS: 162 EUS-FNA biopsies were included in the study. EUS-FNA cytology results were reported according to the six-tiered system of Papanicolaou Cytopathology Society and compared to their final diagnosis with histopathology and/or clinical follow-ups regarding malignancy. The diagnostic yield, the difference in diagnostic accuracy, and the contribution of ROSE to providing the pathologist with adequate tissue uptake (number of slides and cell blocks) for further examination were compared in the ROSE and non-ROSE patient groups. RESULTS: In the non-ROSE group, the diagnostic accuracy according to the final diagnoses was 96% and the sensitivity was 94.44%, specificity 100%, PPV 100%, NPV 87.50%; while diagnostic accuracy was 97.09%, sensitivity 97.47%, specificity 95.83%, PPV 98.77%, NPV 92% in patients with ROSE. There was no significant difference in diagnostic accuracy between those with and without ROSE (p: 0.078). In diagnostic cases, the number of passes, slides and cell blocks were significantly higher in patients with ROSE than those without ROSE (p: 0.003, p: 0.007, p: 0.012, respectively). ROSE was independently associated with diagnostic yield when evaluated by number of passes, slides, cell blocks in regression analysis (p: 0.001, OR: 5.07, confidence interval: 1.89-13.5). CONCLUSION: ROSE may increase the acquisition of sufficient tissue, but it does not have an advantage in diagnostic accuracy. ROSE may raise the number of slides, which may assist the pathologist for the diagnosis. If the lesion is solid and/or contains a solid component, diagnostic yield is higher in patients where ROSE is available. Therefore, ROSE still maintains its applicability in terms of increasing the diagnostic efficiency and making the final diagnosis.