Accuracy of a scoring system for the differential diagnosis of common gastric subepithelial tumors based on endoscopic ultrasonography

Objective We aimed to validate a new scoring system for the differential diagnosis of gastric subepithelial tumors (SET) based on endoscopic ultrasonography (EUS) findings, and to determine its diagnostic yield for different gastric SET. Methods Data of patients with gastric SET treated with endoscopic mucosal resection, endoscopic submucosal dissection or surgical resection from April 2001 to October 2012 at the Soonchunhyang University Hospital (Bucheon, Korea) were retrospectively reviewed. Four variables, including location, shape, layer of origin and echogenicity of the tumor on EUS were used to validate the new scoring system. Results Among the 226 patients with gastric SET, 69 (30.5%) had gastrointestinal stromal tumors (GIST), 68 (30.1%) had ectopic pancreas and 35 (15.5%) had leiomyoma. Most GIST were located at the fundus and body (79.7%), whereas most leiomyomas were found at the cardia (80.0%). Ectopic pancreas was mostly found at the antrum (88.2%). GIST were mainly irregular and round in shape, while ectopic pancreas and lipoma were oval and leiomyomas were irregularly shaped on EUS. With a score range of 0–1 for leiomyoma, 2–3 for GIST, 4–6 for ectopic pancreas and 7–8 for lipoma, the sensitivity and specificity of the scoring system were 75.8% and 85.4% for GIST, 84.6% and 73.1% for ectopic pancreas, 75.9% and 99.5% for leiomyoma and 91.7% and 96.7% for lipoma, respectively. Conclusions The new scoring system was simple and relatively useful for predicting the histology of gastric SET without acquiring tissues. Prospective studies with large sample sizes are needed in the future.