Gastric pseudo-ulcers: membrana angularis and pyloric torus defects.

The membrana angularis and pyloric torus defects are two physiologic bulges which can simulate ulcerations along the lesser curvature of the stomach. The muscular anatomy of the stomach and the mechanism which produces these pseudo-ulcers are discussed. Both pseudoniches can be seen transiently in normal individuals but occasionally are such prominence as to become diagnostic pitfalls. The features and significance of each pseudo-ulcer are reviewed in an attempt to facilitate recognition on the upper gastrointestinal barium examination.