Background: Endoscopic ultrasonography (EUS) has often been used to evaluate gastric subepithelial masses (SEM) and their malignant potential. Information on the use of EUS to survey small gastric SEM is limited.
Methods: A total of 125 consecutive patients referred for evaluation of a suspected gastric SEM were evaluated by EUS from February 2002 to February 2008. Periodic surveillance using EUS or upper gastrointestinal endoscopy was routinely advised. Surgical treatment was considered if a malignant tumor was suspected or symptomatic.
Results: In the 125 patients, EUS found 23 (18.4%) cases of extraluminal compression, 70 (56%) gastrointestinal stromal tumors (GISTs), 9 (7.2%) cases of ectopic pancreas, 5 (4.0%) mucosal tumors, 3 (2.4%) cases of varices, 2 (1.6%) cysts, 2 (1.6%) lipomas, 1 (0.8%) mucosal polyp, 1 (0.8%) submucosal tumor, 6 (4.8%) patients with no abnormality, and 3 (2.4%) unidentified lesions. Surgery was performed in 15 patients, revealing GISTs in 10 patients, and gastrointestinal autonomic nervous tumors (GANTs) in 2 patients as well as other malignant lesions in 3 patients. The pathological findings confirmed that 11 (73.3%) of 15 larger tumors (> 30 mm) were accurately diagnosed. Only 1 of 9 suspected GIST (mean initial tumor size 13.4 +/- 8.3 mm, mean follow-up period 23 months), in the EUS surveillance group significantly increased in size, and surgical pathology disclosed a GIST with intermediate malignant potential.
Conclusions: For evaluating gastric SEM, EUS is able to accurately differentiate intramural from extramural lesions and aid in narrowing the differential diagnosis. In this limited case study, most small gastric SEM (< 30 mm) did not exhibit size changes during follow-up. If the tumor size increases or the ultrasonographic features of a tumor suggest malignant possibility during EUS surveillance, surgical resection should be considered.