Gastric small-cell carcinoma found on esophagogastroduodenoscopy: a case report and literature review.

Introduction. Characterized as an undifferentiated, neuroendocrine tumor arising from totipotent stem cells, small-cell carcinoma (SCC) most commonly arises from the lung. Extrapulmonary small-cell carcinomas (ESCC) are rare and account for only four percent of SCC.