CT versus endoscopic ultrasound for differentiating small (2-5 cm) gastrointestinal stromal tumors from leiomyomas

OBJECTIVE. Abdominal CT or endoscopic ultrasound is recommended for the evaluation of gastric subepithelial tumors. However, few studies have compared the diagnostic performance of these two methods. We compared the diagnostic performance of CT versus endoscopic ultrasound for gastric subepithelial tumors smaller than 5 cm. We also identified significant CT findings associated with the diagnosis of gastrointestinal stromal tumors. MATERIALS AND METHODS. Seventy-one patients with pathologically proven gastric subepithelial tumors were enrolled. We examined the diagnostic performance of CT compared with endoscopic ultrasound. We analyzed CT findings, including the location, long diameter (LD), short diameter (SD), LD-SD ratio, contour, margin, growth pattern, degree and pattern of enhancement, attenuation value, intralesional necrosis, calcification, hemorrhage, surface dimpling, and perilesional lymph node. RESULTS. Endoscopic ultrasound had a sensitivity of 77.6%, specificity of 61.5%, PPV of 90.0%, NPV of 38.1%, and accuracy of 74.6%. CT had a sensitivity of 84.5%, specificity of 53.8%, PPV of 89.1%, NPV of 43.8%, and accuracy of 78.9%. Multivariate analysis revealed that the presence of intralesional necrosis (odds ratio [OR], 10.88; p = 0.037) and an LD-SD ratio less than 1.5 (OR, 32.37; p = 0.002) were independent CT findings for the diagnosis of gastrointestinal stromal tumors. CONCLUSION. CT is as effective as endoscopic ultrasound for the diagnosis of gastric subepithelial tumors smaller than 5 cm. Tumors with intralesional necrosis and an LD-SD ratio less than 1.5 may require further pathologic diagnosis.