An unusual case of synchronous gastric
carcinomas occurred in a 28-year-old man with a family history of
gastric disease. Two
tumor foci were identified: a well-differentiated advanced
carcinoma with the phenotypic properties of complete intestinal
metaplasia and an early intestinal-type
carcinoma. Histochemical and immunohistochemical stains to demonstrate complete intestinal
metaplasia, ie,
Alcian blue pH 2.5/
periodic acid-Schiff,
high iron diamine/Alcian blue pH 2.5, CD10, and MUC2, were all positive in the advanced
adenocarcinoma. Of all markers used, only
high iron diamine/Alcian blue pH 2.5 and
Alcian blue pH 0.5 were positive in the early
carcinoma. In these cases, mistakes frequently are made during examination of endoscopic biopsies. Fortunately, the advanced
adenocarcinoma was low grade (the patient has shown no signs of disease at 6 years postsurgery). Histopathologic, histochemical, and immunohistochemical findings suggest that an extensive substrate of complete intestinal
metaplasia (corpus) and of complete and incomplete intestinal
metaplasia (antrum) can be associated with two independent
tumors with different phenotypes.