Histopathological comparison of aspiration and biopsy needles in endoscopic ultrasound‐guided tissue acquisition in patients with subepithelial lesions

Background Information on whether a fine‐needle biopsy (FNB) needle can improve histopathological specimen quality or the amount of core tissue collected in the diagnosis of subepithelial lesions (SELs) remains insufficient. In this study, we aimed to compare the procedure outcomes and adequacy of histopathological specimens of fine‐needle aspiration (FNA) and FNB needles in endoscopic ultrasound‐guided tissue acquisition (EUS‐TA) using sample isolation processing by stereomicroscopy (SIPS) in patients with SELs. Methods We performed a retrospective comparison of SEL cases registered in two previously conducted prospective studies. Of 61 cases, we identified 56 cases of SELs that involved the muscularis propria layer. Of these, 27 patients who underwent EUS‐TA using a 22‐gauge FNA needle between July 2016 and December 2017, and 29 patients who underwent the procedure using a 22‐gauge FNB needle between March 2018 and January 2019 were included in the FNA and FNB group, respectively. Results Patient background characteristics did not differ between the groups. The technical success rate was 100% in both groups. The median adequacy score was significantly higher in the FNB group than in the FNA group (P