Summary

• Commonly presents with flushing and diarrhoea. Other clinical features include wheeze, palpitations, telangiectasia, and abdominal pain.
• Symptoms develop due to secretion of serotonin, kinins, and other biogenic amines from functional secretory neuroendocrine tumours.
• Diagnosed by elevated levels of urinary 5-hydroxyindoleacetic acid. Chromogranin A often elevated in the presence of liver metastases.
• Treatments include medical therapies (somatostatin analogues, radionuclide therapies) and surgical options (resection of primary and secondary tumours).
• Complications include carcinoid heart disease and carcinoid crisis at times of stress (e.g., during surgery).