Randomized crossover trial comparing EUS-guided fine-needle aspiration with EUS-guided fine-needle biopsy for gastric subepithelial tumors.

Aim: The purpose of this study is to compare the diagnostic yield of endoscopic ultrasound (EUS)-guided fine-needle aspiration (EUS-FNA) and EUS-guided fine-needle biopsy (EUS-FNB) for gastric subepithelial tumors (SET). Methods: Patients diagnosed SET derived from fourth layer of the stomach were prospectively enrolled and randomly assigned to undergo both EUS-FNA using standard needle and EUS-FNB using a core biopsy needle alternatively to the same lesion a total of four times per session. The specimen was carefully examined for the presence of a macroscopic visible core, appearing as threadlike yellowish or bloody pieces of tissue and blinded histocytologic analyses were conducted. For spindle cell lesions by hematoxylin and eosin staining (H&E) on histologic evaluation, immunohistochemical staining was performed in all cases to confirm the pathological diagnosis. Results: A total of 23 patients were enrolled and underwent paired EUS-FNA and -FNB sampling. The diagnostic rate due to immunohistochemical staining was 73.9% and 91.3%, respectively (P = .120). The rate of obtaining specimens with a macroscopic yellowish core and only a bloody core among the tissue specimens were respectively 43.5% and 52.2% for EUS-FNA and 69.6% and 30.4% for EUS-FNB. The diagnostic rate for a yellowish core (84.6%) and a bloody core (84.2%, P =.971) did not differ significantly. Conclusion: Both techniques were equivalently safe and successful in terms of a high diagnostic yield for gastric SET. And the tissue that can be immunohistochemically stained is present even in the specimens that appear to be a macroscopically bloody core.