Clinical course of small gastric subepithelial lesion less than 20 mm diagnosed by endoscopic ultrasound-guided fine-needle aspiration.

Approximately 40% of small gastric SELs were malignant tumors, such as GIST, with most of them requiring treatment. Additionally, considering that the EUS measurement is 5 mm smaller than the pathological tumor diameter, further examinations, such as systematic EUS-FNA, may be required for SEL, including those smaller than 20 mm.