Abstract
The present study aimed to evaluate the clinical value of macroscopic on-site evaluation (MOSE) of solid masses by endoscopic ultrasound (EUS)-guided fine needle aspiration (FNA) using a standard 22-gauge needle and to explore the cut-off length of macroscopic visible core (MVC) required to obtain an accurate histopathological diagnosis. In total, 119 patients who satisfied the inclusion and exclusion criteria and underwent EUS-FNA were divided into conventional FNA and FNA combined with MOSE groups. In the MOSE group, the presence of MVC was examined and its total length measured, after which the pathological results of FNA were compared with the final diagnosis. The diagnostic sensitivity, specificity, accuracy, positive predictive value (PPV) and negative predictive value (NPV) of FNA in the two groups were calculated and the effect of MOSE on the FNA result was analyzed. The MOSE group had a higher diagnostic sensitivity (75.0% vs. 89.8%; P=0.038) and accuracy (74.5% vs. 90.6%; P=0.026). MVC was observed in 98.4% (63/64) of patients in the MOSE group. The median length of MVC was 15 mm. The optimal cut-off length of MVC for obtaining an accurate histological diagnosis was 13 mm, with a sensitivity of 90.2%. No statistically significant significance was observed in the specificity, PPV and NPV between the groups. Thus, MOSE helps to improve the diagnostic ability of FNA for solid masses and may be a useful alternative to assess the adequacy of puncture specimens in units where rapid on-site evaluation cannot be performed.