Efficacy and histologic frequencies of endoscopic ultrasonography‐guided tissue acquisition using conventional fine‐needle aspiration needles for gastric subepithelial hypoechoic mass

Abstract

Introduction/PurposeFor gastric subepithelial lesions (GSELs) showing a hypoechoic mass (HM) on endoscopic ultrasonography (EUS) imaging, the utility of EUS‐guided tissue acquisition using conventional fine‐needle aspiration needles (EUS‐TA‐CFNAN) and the frequency of histological types remain unclear. This study aimed to examine this issue.MethodsThis prospective observational study enrolled 291 consecutive patients who underwent EUS‐TA‐CFNAN for GSELs showing an HM (GSELHM) on EUS imaging. Immunohistochemical analysis was performed for all EUS‐TA‐CFNAN and surgically resected specimens. The main outcome measures were the technical results of EUS‐TA‐CFNAN and the frequency of histological types in GSELHM.ResultsThe endoscopic ultrasound‐guided tissue acquisition using conventional fine‐needle aspiration needle diagnosis rate for GSELHM was 80.1% (95% confidence interval [CI]: 75.0–84.5, 233/291). It was significantly lower for antrum (P = 0.004) and lesions smaller than 2 cm (P = 0.003). There were no adverse events. The immunohistochemical diagnoses of EUS‐TA‐CFNAN included 149 cases of gastrointestinal stromal tumour (GIST) (51.2%), 48 cases of leiomyoma (16.5%), 11 cases of schwannoma (3.8%), 8 cases of the ectopic pancreas (2.7%), 5 cases of subepithelial lesion like cancer (1.7%), 12 cases of other lesions (4.1%), and 58 cases of undiagnosable lesions (19.9%). The frequency of malignant or potentially malignant tumour in GSELHM was 55.0% (95% CI: 49.1–60.8, 160/291). Surgery was performed in 149 patients according to the conclusive EUS‐TA‐CFNAN results, in which the diagnostic accuracy of EUS‐TA‐CFNAN was 97.3% (95% CI: 94.7–99.9, 145/149).ConclusionThe use of EUS‐TA‐CFNAN for GSELHMs is safe and accurate. Gastric subepithelial lesions showing a hypoechoic mass have a reasonably high possibility of containing malignant or potentially malignant tumours, including GISTs.