Endoscopic diagnosis of early gastric cancer by the endoscopic Congo red-methylene blue test.

The endoscopic Congo red test combined with dyeing with methylene blue was performed in 85 patients with early gastric cancer (94 lesions). Results revealed that gastric cancer bleached the Congo red and methylene blue sprayed over their surface and this appeared in sharp contrast to the red-colored mucosa of unaffected areas. Grossly, polypoid and flat types, and histologically differentiated adenocarcinomas bleached the dyes more frequently and more intensely than depressed and undifferentiated adenocarcinomas. Thus the spread of cancerous growth could be judged rather accurately and so the target area could be reached by biopsy in cases where there were few if any visual signs of abnormality.