The first patient was a man in his eighties who visited our department because of anemia. Gastrofiberscopy revealed a bleeding submucosal tumor, approximately 50mm in diameter, in the cardia ofthe stomach. Considering that he underwent coronary-artery bypass surgery and received 3 oral antithrombotic medicines, his bleeding tendency was so high that we decided to choose partial gastrectomy. A postoperative histopathological examination revealed that the tumor was a small cell endocrine carcinoma. The second patient was a woman in her seventies. She had consulted her personal physician because of gastric ulcers; periodic gastrofiberscopy revealed a type 3 gastric cancer, approximately 40mm in diameter, on the posterior wall ofthe middle section ofher stomach. It was histologically diagnosed as a poorly differentiated neuroendocrine carcinoma. On a preoperative blood examination, the levels ofhormones such as glucagon, serotonin, and gastrin were within their respective normal limits. Total gastrectomy was performed, and she received oral S-1 for adjuvant chemotherapy since her discharge from the hospital.