Macroscopic onsite evaluation using endoscopic ultrasound fine needle biopsy as an alternative to rapid onsite evaluation.

Background and aims  This study aimed to evaluate the performance of Macroscopic On-site Evaluation (MOSE) using a novel endoscopic ultrasound (EUS) fine needle biopsy (FNB) needle (22-G Franseen-tip needle, Acquire, Boston Scientific Incorporated, Boston, Massachusetts, United States), and without using Rapid On-Site Evaluation (ROSE). Method  Between May 2016 and August 2016, all consecutive patients referred to our center for EUS tissue acquisition (TA) for solid lesions underwent EUS-FNB with the 22-G Franseen-tip needle unless contra-indicated. The operator performed MOSE. If no macroscopic core was visualized, a second pass was performed. The final diagnosis was defined as unequivocal histology from EUS-TA with compatible 18 months follow-up, surgical resection, or both. We retrospectively analyzed the performance of MOSE. Results  A total of 46 consecutive patients was included, and 54 solid lesions were biopsied. The endosonographer visualized core tissue in 93 % (50/54) of targets with a single pass, of which the pathologist confirmed histologic core fragments in 94 % (47/50). Four lesions required two passes, and the overall correlation between MOSE and histologic core fragments was 94 % (48/51). Diagnostic adequacy was 98 % (53/54) with one biliary target biopsied without significant material. The overall diagnostic accuracy was 94 %. Sensitivity, specificity, positive predictive value, and negative predictive value for malignancy were 92 %, 100 %, 100 %, and 81 %, respectively. No adverse events were reported. Conclusion  Our study demonstrated that MOSE using the 22-G Franseen-tip needle could limit needle passes by accurately estimating histologic core fragments. It also demonstrated that high diagnostic adequacy and accuracy of > 90 % could be achieved without ROSE.