Evaluation of endoscopic ultrasonography for gastric tumors and presentation of three-dimensional display of endoscopic ultrasonography

Summary

We have studied the usefulness of endoscopic ultrasonography (EUS) for: (1) differentiation between extragastric mural compression (EGMC) and submucosal tumors (SMT); (2) qualitative assessment of these lesions; (3) diagnosis of serosal invasion by malignant gastric tumors; (4) presentation of three-dimensional display of EUS findings. A total of 103 patients with submucosal lesions protruding into the gastric lumen on endoscopy were examined. Differentiation between EGMC and SMT could be made by EUS in all cases. Qualitative assessment of these lesions was made by observing their EUS findings, i.e. their internal and marginal echo pattern and their location in the gastric layers. The correct diagnosis was made in 88% (23/26) of EGMC. Of 50 patients with SMT, comprising myogenic tumor (32), aberrant pancreas (8), lipoma (3), gastric cyst (4) and malignant lymphoma (elevated type; 3), differentiation between malignant and benign myogenic tumors was impossible by EUS alone. In addition, 48 patients with advanced gastric cancer and malignant lymphoma were examined. Invasion to the serosal surface was diagnosed as interruption of the fifth layer of the gastric wall. Invasion to other organs was diagnosed by interruption and fusion of the fifth layer into the border of the adjacent structure. Serosal invasion was diagnosed accurately in 65% of 48 patients. Microscopic invasion was difficult to diagnose, and gastric stenosis by tumor was an obstacle to adequate scanning. EUS can be valuable in the differential diagnosis between EGMC and SMT and in the qualitative diagnosis of gastric lesions. It is also effective in detecting serosal invasion by gastric malignant tumors. Three-dimensional display of pathological lesions is new in EUS. With this method, it is easy to get the stereograph and to obtain a complete picture of the lesions. We present two cases in this report.