[A neoplasm with neuroendocrine differentiation involving any part of the gastrointestinal system. It includes well differentiated neuroendocrine tumors (carcinoid tumors), poorly differentiated neuroendocrine tumors (small cell carcinomas), and hormone producing pancreatic endocrine neoplasms. ( NCI )]
UMLS (NCI) C1333799Gastrointestinal Neuroendocrine Tumor