Gastric Submucosal Tumor (Leiomyoma, GIST, etc.) and LECS

Abstract

SMTs such as gastrointestinal stromal tumor (GIST) and leiomyomas appear as a submucosal mass with smooth margins, a normal overlying mucosa, and bulging into the gastric lumen. On endoscopic ultrasound (EUS), GISTs are mainly derived from the fourth layer (corresponding to the muscularis propria). They appear well-demarcated as heterogeneous lesions with a mixture of a low-echoic and high-echoic lesions. Malignancy might be suspected in cases of rapid growth, central ulceration, and/or irregular borders in endoscopic examinations. The combined presence of EUS findings (irregular extraluminal margins, cystic spaces, and lymph nodes with a malignant pattern) had a high positive predictive value for a malignant or borderline GIST [1].