- Etiology: derived from enterochromaffin cells – not present under the age of 4 years
- Imaging: most common sites – ileum and appendix, enhancing soft tissue mass or bowel wall thickening with +/- mesenteric fibrosis, gallium-68 octreotide PET/CT vs. indium-111 pentetreotide SPECT/CT vs. indium-111 octreotide SPECT/CT vs iodine-123 MIBG
- Complications: ileal and cecal carcinoids commonly metastasize
- Clinical: carcinoid syndrome if spread to the liver or beyond, elevated levels of urinary 5-hydroxyindoleacetic acid (5-HIAA)