Subepithelial lesions (SELs) arise from the wall of the gastrointestinal (GI) tract and can originate from the muscularis mucosa, submucosa, or muscularis propria. Most SELs are small and usually found incidentally on endoscopy or on cross-sectional imaging. Although most of these lesions are benign, approximately 15% have the potential for malignant transformation. The potential for progression varies considerably based on size, location in the GI tract, and histology, and these features, in turn, inform the most appropriate treatment strategy regarding need for surveillance or resection. Definitive diagnosis with biopsy or endoscopic ultrasound–guided fine-needle aspiration or fine-needle biopsy is not always possible. Indeed, results of fine-needle aspiration and fine-needle biopsy are highly variable and operator-dependent, with diagnostic yields ranging from as low as 20% to >90%. Although surgery has been the traditional method for the management of select neoplastic SELs, recent advances in less invasive endoscopic techniques have been introduced as potential alternatives for both diagnosis and treatment.
Endoscopic full-thickness resection (EFTR) has emerged as a novel treatment option for select SELs. EFTR involves the local resection of a tumor, often necessitating dissection through the adjacent muscularis propria to achieve complete resection. This can be done with an “exposed” or a “nonexposed” technique. The term exposed refers to resection of all layers of the wall, including the mucosa. A nonexposed approach either preserves an overlying flap of mucosa, as in the submucosal tunneling endoscopic resection (STER) technique, or uses a “close first, then cut” method to avoid the impending perforation. In this commentary, we reviewed the different techniques and uses of EFTR for the management of SELs. Recent guidelines offer a more comprehensive review of the diagnosis and management of SELs of the GI tract, which are beyond the scope of this commentary.
