NCIt definition : An epithelial neoplasm with neuroendocrine differentiation. This category includes
neuroendocrine tumors, neuroendocrine carcinomas, and paragangliomas.;
Alternative definition : NCI-GLOSS: A tumor that forms from cells that release hormones in response to a signal
from the nervous system. Some examples of neuroendocrine tumors are carcinoid tumors,
islet cell tumors, medullary thyroid carcinomas, pheochromocytomas, and neuroendocrine
carcinomas of the skin (Merkel cell cancer). These tumors may secrete higher-than-normal
amounts of hormones, which can cause many different symptoms.;