Prevalence of potentially malignant lesions in small gastric subepithelial lesions undergoing surgical resection according to the risk features

Objectives: Current guidelines recommend endoscopic surveillance for small subepithelial lesions (SELs).However, differentiating neoplastic lesions from benign entities based solely on imaging findings remains challenging.This study aimed to evaluate the prevalence of potentially malignant lesions in patients with small gastric SELs who underwent surgical resection. Materials and Methods:We retrospectively analyzed 222 surgically resected small gastric SELs (preoperatively measured as ≤3 cm) from 220 patients treated between 2014 and 2022.Patients were stratified into three risk groups according to tumor size (≥2 cm), interval growth, and high-risk features on endoscopic ultrasonography and computed tomography: Group 1, lesions <2 cm with no risk features; Group 2, <2 cm with any risk features; and Group 3, ≥2 cm.Results: Pathological examination revealed gastrointestinal stromal tumors (GISTs) in 55.0% of lesions and neuroendocrine tumors (NETs) in 3.2%.Among the GISTs, 33 (27.0%) were classified as very low risk, 67 (54.9%) as low risk, 14 (11.5%) as intermediate risk, and 8 (6.6%) as high risk.The prevalence of neoplastic lesions increased across the risk groups (43.2% in Group 1, 57.8% in Group 2, and 62.1% in Group 3); however, this trend did not reach statistical significance (P=0.117).In analyses of predictors of neoplastic SELs, tumor size, interval growth, and high-risk imaging features were not significantly associated with neoplasia.Conclusions: Potentially malignant pathology was observed in a substantial proportion of surgically resected small gastric SELs, including very small lesions (<2 cm) without risk features.Accordingly, resection may be considered as one management option to obtain a definitive diagnosis and provide treatment, alongside surveillance strategies.