Abstract:Endoscopic ultrasonography has become an important diagnostic procedure complementary to endoscopy and histopathological study in the preoperative evaluation of gastric carcinoma. Despite allowing visualization of tumoral infiltration with quite high accuracy, certain factors have limited the accuracy of this modality or even led to misinterpretation. We designed a prospective study to evaluate the accuracy of gastric carcinoma diagnosis with special reference to factors resulting in misdiagnosis. During a 22 month period, 86 patients with early and advanced gastric carcinoma underwent surgical or endoscopic resection on the basis of endosonographic findings. In all patients, endosonographic findings, location and macroscopic type of the tumor and histopathological characteristics including depth of invasion, malignant cell type and/or differentiation, and the presence/absence of ulceration in the tumor focus were recorded. The endosonographic and histopathological results were compared at the end of the study. Overall accuracy was 85% using the TNM staging system. There were no significant differences in accuracy in the location of the tumor, histological grading or macroscopic type of tumor, although the accuracy rate was lower for tumors located in the antrum. Ulceration in the tumor focus was a major factor leading to misinterpretation of the findings of early gastric cancer (p<0.02). The diagnosis of microinvasion is an issue which remains to be resolved.