[Diagnosis and Management of Asymptomatic Upper Gastrointestinal Subepithelial Lesions]

Upper gastrointestinal subepithelial lesions (SELs) are detected during routine screening endoscopy and are usually identified as asymptomatic protrusions covered by normal-appearing mucosa. Although most SELs follow a benign clinical course, some lesions, including gastrointestinal stromal tumors, neuroendocrine tumors, lymphomas, and metastatic tumors, possess malignant potential and require further evaluation. Appropriate risk stratification is therefore essential to guide management. Endoscopy remains the initial diagnostic modality, while endoscopic ultrasonography (EUS) plays a central role in characterizing lesion size, layer of origin, echogenicity, and other high-risk features. Recent advances in tissue acquisition techniques, including EUS-guided fine-needle biopsy and mucosal incision-assisted biopsy, have improved diagnostic yield and histologic accuracy. Accumulating evidence from large retrospective and prospective studies indicates that most small asymptomatic SELs remain stable during long-term follow-up, whereas larger lesions, interval growth, mucosal surface changes, and suspicious EUS findings are associated with an increased risk of progression. Management strategies should be individualized according to lesion characteristics, malignant potential, and patient factors. Surveillance is generally appropriate for small lesions without high-risk features, while tissue diagnosis or resection should be considered for lesions demonstrating growth, symptoms, or imaging findings that are concerning. Advances in therapeutic endoscopy, including endoscopic submucosal dissection, submucosal tunneling endoscopic resection, and endoscopic full-thickness resection, have expanded minimally invasive treatment options. Current international and Korean guidelines emphasize EUS-based risk assessment and selective intervention rather than routine resection of all SELs. This review summarizes the epidemiology, natural history, diagnostic approaches, management strategies, and current guideline recommendations for asymptomatic upper gastrointestinal SELs.