The efficacy of rapid on-site evaluation during endoscopic ultrasound-guided fine needle aspiration of pancreatic masses

Background Endoscopic ultrasound (EUS)-guided fine needle aspiration (FNA) has become the preferred method to diagnose pancreatic masses due to its minimally invasive approach and diagnostic accuracy. Many studies have shown that rapid on-site evaluation (ROSE) improves diagnostic yield by 10-30%; however, more recent studies have demonstrated effective diagnostic accuracy rates without ROSE. Our study aims to examine whether the current standard of performing ROSE after each FNA pass adds diagnostic value during EUS-guided FNA of pancreatic masses. Methods We conducted a retrospective case series on patients who underwent EUS-guided FNA of pancreatic masses between February 2011 and October 2014. All cases were performed by one of three endoscopists at Emory University Hospital. Patient demographics, radiologic details of pancreatic masses and pathology reports of the biopsied pancreatic masses were examined. Results A total of 184 procedures performed in 171 patients were reviewed. The final pathology reports of the biopsied pancreatic masses showed 128 (70%) with confirmed malignancy. Only 64 (50%) of these 128 cases initially showed malignant cells during ROSE. Among these 64 cases, 23% required 5 or more FNA passes to first detect malignant cells. Conclusions The use of ROSE during EUS-guided FNA of pancreatic masses may increase the diagnostic yield, since malignant cells were often detected during later FNA passes that would otherwise be missed if tissue sampling stopped prematurely. In addition, sample preparation for ROSE may be suboptimal, since malignant cells were only detected in 50% of cases.