Neuroendocrine tumor

Neuroendocrine tumors (NETs) are neoplasms that arise from cells of the endocrine (hormonal) and nervous systems. They most commonly, but not only, occur in the intestine, where they are often called carcinoid tumors.

Although there are many kinds of NETs, they are treated as a group of tissue because the cells of these neoplasms share common features, including a similar histological appearance, having special secretory granules, and often producing biogenic amines and polypeptide hormones.

The term "neuro" refers to the dense core granules, similar to those in serotonergic neurons that store monoamines. The term "endocrine" refers to the synthesis and secretion of these monoamines. The neuroendocrine system includes endocrine glands such as the pituitary, the parathyroids and the neuroendocrine adrenals, as well as endocrine islet tissue embedded within glandular tissue such as in the pancreas, and scattered cells in the exocrine parenchyma. The latter is known as the diffuse endocrine system.

There are several treatments available for neuroendocrine tumors, including surgery, systemic treatments such as chemotherapy and peptide receptor radionuclide therapy, and others. Treatments may be aimed at curing the disease or at relieving symptoms.