Carcinoid and neuroendocrine disease is a rare cancer affecting less than 5 in 100,000 persons.
 
Carcinoid cancer and related neuroendocrine tumors (NETs) are small, slow growing tumors found mostly in the gastrointestinal system and other parts of the body such as the pancreas and the lung. These are slow growing tumors compared to other cancers and it usually takes many years before they become large or cause symptoms.
 
Carcinoid tumors and other NETs usually originate in the endocrine or hormone-producing cells in endocrine organs like the pancreas, gastrointestinal tract, testes, ovaries or lungs. Carcinoid tumors can produce symptoms due to excess production of hormone substances, such as serotonin, bradykinin, histamine, and prostaglandins. Excess levels of these substances can sometimes result in a diverse set of symptoms called carcinoid syndrome.