An intestinal tumour, especially in the appendix, which causes diarrhoea.
A tumor derived from the neuroendocrine cells in the intestinal tract, bile ducts, pancreas, bronchus, or ovary. It secretes serotonin (5-hydroxytryptamine) and other vasoactive substances.
A non-cancerous growth that originates from cells found in the appendix or other intestinal tissues. Under a microscope, it may appear similar to cancer, but it does not result in any noticeable symptoms.