Endoscopic ultrasonography of normal and pathologic upper gastrointestinal wall structure. Comparison of studies in vivo and in vitro with histology.

Endoscopic ultrasonographic analysis of the upper gastrointestinal wall was performed in vivo (preoperatively) and in vitro (resection specimen or postmortem material). The images obtained were correlated with histology. The normal intestinal wall was visualized as a five layer structure. The wall structure was interpreted as abnormal when partial or total destruction of the wall architecture was visualized. A diffuse submucosal hypoechoic structure without penetration into the muscularis propria was indicative of a benign lesion. Diffuse irregular hypoechoic echo pattern penetrating into the muscularis propria, with or without alteration of the mucosal layer, was usually found in linitis plastica. As a rule, early gastric cancer could readily be differentiated from advanced gastric cancer when penetration of the lesion into the muscularis propria appeared to be absent. Follow-up EUS was helpful in the differentiation between a benign and malignant ulcer. Remaining sonographic abnormalities after successful treatment of an ulcer was compatible with malignancy. Further in vivo and vitro studies must be performed to determine the accuracy and limitations with which the ultrasonographic findings are interpreted.