A condition in which the neuroendocrine cells develop into tumours.A neuroendocrine tumour may grow slowly or aggressively and spread to other parts of the body.Many people do not develop symptoms and the tumour is detected incidentally. When symptoms occur, they can vary based on the location of the tumour. In rare cases, skin flushing or fluctuating blood sugar levels may occur.Treatment depends on the type of tumour. Some approaches may include surgery, radiation and chemotherapy. Neuroendocrine tumors are cancers that begin in specialized cells called neuroendocrine cells. Neuroendocrine cells have traits similar to those of nerve cells and hormone-producing cells. Neuroendocrine tumors are rare and can occur anywhere in the body