RESUMO
We present a case of a primary advanced gastric tumor that was composed of 2 different pathological components: small cell carcinoma and moderately-differentiated adenocarcinoma. The patient was still alive four years after the surgery was performed, without recurrence. A large part of the tumor consisted of a diffuse sheet of small cell carcinoma, which transitioned into another small portion consisting of moderately-differentiated tubular adenocarcinoma components. Therefore, this case raised the possibility that small cell gastric carcinoma may originate from totipotential stem cells of the stomach. Although small cell carcinoma progresses aggressively, and patients with it have an extremely poor prognosis, this patient recovered uneventfully after the surgical resection, and has remained in good health, without any recurrences.