Carcinoid syndrome Flashcards
Define:
Constellation of symptoms caused by systemic release of humoral factors from carcinoid tumours (tumours of neuroendocrine cells)
Aetiology/risk factors:
• Carcinoid tumours are slow-growing neuroendocrine tumours
They are mostly derived from serotonin-producing enterochromaffin cells (neural crest origin)
Common sites: appendix, ileum, rectum
They produce secretory products like serotonin, histamine, tachykinins, kallikrein and prostaglandins
75-80% of patients with carcinoid syndrome have small bowel carcinoids
Epidemiology:
- RARE
- UK incidence: 1/1,000,000
- Asymptomatic carcinoid tumours are more common
- 10% of patients with MEN-1 have carcinoid tumours
Symptoms:
• Paroxysmal FLUSHING • Diarrhoea • Crampy abdominal pain • Wheeze • Sweating • Palpitations • Hepatic metastases may cause RUQ pain Shortness of breath
Signs:
- Facial flushing
- Telangiectasia (threaded red lines on skin)
- CCF – tricuspid incompetence and pulmonary stenosis from serotonin induced fibrosis
- Wheeze
- Right-sided murmurs (tricuspid stenosis/regurgitation or pulmonary stenosis)
- Nodular hepatomegaly in cases of metastatic disease
- Carcinoid Crisis Signs
Signs of carcinoid crisis:
Occurs when a tumour outgrows its blood supply or is handled too much during surgery causing mediators to flood out – causes vasodilation, hypotension, tachycardia, bronchoconstriction and hyperglycaemia
o Profound flushing
o Bronchospasm
o Tachycardia
o Fluctuating blood pressure
Investigations:
o Check 5-HIAA (5-hydroxyindoleacetic acid) levels (metabolite of serotonin)
Blood
o Plasma chromogranin A and B – reflects tumour mass
o Octreoscan – to identify tumour – uses octreotide (Somatostatin analogue)
o Fasting gut hormones
CT or MRI Scan
o To localise the tumour
Radioisotope Scan
o Radiolabelled somatostatin analogue (octreotide) helps localise the tumour
Investigations for MEN-1
Echo and BNP can be used to investigate carcinoid heart disease
