Endoscopic ultrasound evaluation of indeterminate subepithelial lesions of the upper gastrointestinal tract

EUS: endoscopic ultrasound; GIST: gastrointestinal stromal tumor; FNA: fine-needle aspiration; FNB: fine-needle biopsy.

* A normal-appearing five-layered gastrointestinal wall structure is seen interposed between the lesion and the bowel lumen. Extramural lesions may be normal adjacent structures (eg, spleen, aorta, gallbladder) or pathologic structures (eg, splenic artery aneurysm, cyst, tumor). Rarely, the distinction between an intra- and extramural lesion may be difficult if there is invasion of an extramural lesion into the gastrointestinal wall.

¶ Tissue sampling is not required to confirm the diagnosis.

Δ Options for tissue sampling include EUS-FNA, EUS-FNB, unroofing the lesion followed by forceps biopsy, and endoscopic resection. The choice of approach will depend on the lesion's characteristics (eg, size and location) and the experience of the endoscopist performing the procedure.

◊ Tissue sampling should be performed to confirm the diagnosis.

§ Visualization of three or five layers in the wall of the lesion suggests a duplication cyst.