Invasion of the duodenum by carcinoma of the stomach.

It has frequently been stated that extension to the duodenum occurs commonly in patients with gastric lymphoma but almost never in those with carcinoma of the stomach. We found radiographically detectable invasion of the duodenum in six of 111 consecutive patients (5%) with gastric carcinoma. The duodenum was involved microscopically in 18%. Radiographic abnormalities in the duodenum in 11 patients with proven transpyloric spread of tumor varied from irregularity of the base of the bulb narrowing and distortion extending well into the second portion of the duodenum. On the basis of these data and the reported frequency of transpyloric extension in gastric lymphoma, carcinoma appears to be the more likely diagnosis in a patient with duodenal involvement by an antral tumor.