A neuroendocrine tumour (NET) is a type of cancer made up of specialized neuroendocrine cells. Neuroendocrine tumours can be found almost anywhere in the body. Another name for this type of cancer is neuroendocrine neoplasm (NEN).
Neuroendocrine cells are a specialized type of cell that are found throughout the body. Neuroendocrine cells produce chemicals called hormones that act as a signal to influence the function of nearby cells.
All neuroendocrine tumours are considered malignant (cancerous) because all have the potential to metastasize (spread) to other parts of the body. However, the risk of metastasis depends on several factors including the type of neuroendocrine tumour, the size of the tumour, and the tumour grade. For example, a carcinoid is a type of neuroendocrine tumour in the lungs that is considered low grade and has a very low risk of metastasis. In contrast, neuroendocrine carcinoma is a high grade type of neuroendocrine tumour that commonly metastasizes to other parts of the body.
Neuroendocrine tumours are commonly found in the pancreas, lungs, small intestine, large intestine (colon), skin, breast, kidneys, thyroid gland, and reproductive organs.
Neuroendocrine tumours are divided into two groups: tumours made up of epithelial neuroendocrine cells and those made up of non-epithelial neuroendocrine cells. Tumours made up of epithelial neuroendocrine cells are further divided into well differentiated neuroendocrine tumours and poorly differentiated neuroendocrine carcinomas. Tumours made up of non-epithelial neuroendocrine cells are called paragangliomas. Pheochromocytoma is a special type of paraganglioma found in the medulla of the adrenal cortex.
Atypical carcinoid tumour of the lungs
Large cell neuroendocrine carcinoma of the lungs
Small cell carcinoma of the lungs
Well differentiated neuroendocrine tumour of the stomach
Well differentiated neuroendocrine tumour of the appendix
Well differentiated neuroendocrine tumour of the pancreas
Well differentiated neuroendocrine tumour of the colon and rectum
Poorly differentiated neuroendocrine carcinoma of the colon and rectum
North American Neuroendocrine Tumour Society