[Two cases of gastric cancer expressing Glypican 3, but producing AFP with different lectin affinity]

We encountered 2 cases of AFP-producing gastric cancer. In the first patient, an 82-year-old man was found to have advanced type II advanced carcinoma in the stomach with a massive tumor embolus in the portal vein. In the second case, an 80-year-old man was given a diagnosis of multiple liver metastases of gastric cancer with portal vein thrombosis. Our diagnosis of gastric cancer in both cases was AFP-producing. It was supposed that the elevation of serum level of AFP might be caused by enteroblastic differentiation in the first case and hepatoid differentiation in the second case. Although, in both cases, the biopsy specimens of the gastric neoplasm proved moderately to poorly differentiated adenocarcinoma without hepatoid differentiation, the localization of Glypican 3 in gastric cancer cells was observed using immunostaining with a monoclonal antibody. In both cases, Glypican 3 was a sensitive and useful marker for AFP-producing gastric cancer with or without hepatoid differentiation.