In the digestive system, there are some glands called the neuroendocrine system. It is the job of these glands to create hormones (chemicals the body needs) to go into the blood stream. A Carcinoid tumour is when the cells in the neuroendocrine system keep dividing to create a lump in this system. Most cancer tumours of the neuroendocrine system are found in the small bowel or the appendix.