Distributed Sample Allocation for the Diagnosis of Mass Lesions by EUS-FNA

Background: Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA)is a well-established, minimally invasive, interventional diagnostic endoscopic technique for the identification of mass lesions; however, its diagnostic accuracy needs further improvement. Most previous studies have focused on the choice of puncture techniques, and rare studies have investigated the effect of distributed sample allocation on the diagnostic accuracy of EUS-FNA. In this study, we aim to investigate the effect of distributed versus nondistributed sample allocation on EUS-FNA diagnostic accuracy. Methods: A total of 248 patients with mass lesions indicated by previous imaging examination were enrolled in this study. The patients were randomly assigned to 2 groups: distributed and nondistributed sample allocation. Clinicopathological features were collected retrospectively and analyzed. Results: Distributed sample allocation can raise the overall EUS-FNA diagnostic accuracy from 88.31% (nondistributed preservation) to 96.34% (distributed preservation). Distributed sample allocation was effective to further increase EUS-FNA diagnostic accuracy ( P =0.0262). Furthermore, for lesions of different locations, the diagnostic accuracy of EUS-FNA of lesions in the mediastinum and lung has improved ( P =0.0128). For lesions of different echogenicity, distributed allocation has effectively improved the diagnostic rate in cystic solid lesions ( P =0.0235). Conclusion: As a rarely considered approach, distributed sample allocation can improve the overall diagnostic accuracy of EUS-FNA.