Carcinoid syndrome
Incidence: 1 per 500 000 per year.
Features
- intermittent cyanotic flushing
- diarrhoea & vomiting, abdominal cramps
- bronchoconstriction: cough, wheeze, dyspneoa
- pulmonary stenosis, tricuspid regurgitation (smooth muscle plaques deposited in endocardium).
- hepatomegaly (metastases)
May also present with features of ↑gastrin, ↑ACTH, ↑insulin.
Δx. excess 5HIAA in 24h urine.
Causes
Neuroendocrine tumours of
- appendix
- rectum
- lungs (usually central)
- ileum, stomach, colon
- pancreas
- biliary tree
- liver
Midgut tumours 50%. Bronchial tumours 10%. Gut carcinoids are silent unless they metastasise to the liver.
Treatment
- Surgical resection
- Symptomatic relief Rx. octreotide
- Tumour targetted radiotherapy with 131I-MIBG