Carcinoid syndrome Flashcards
1
Q
What is carcinoid syndrome?
A
Constellation of symptoms caused by systemic release of humoral factors (biogenic amines, polypeptides, prostaglandins) from carcinoid tumours
2
Q
What is the aetiology of carcinoid syndrome?
A
- Carcinoid tumours are slow growing neuroendocrine tumours mostly derived from serotonin-producing enterochromaffin cells - They produce secretory products such as serotonin, histamine, tachykinins, kallikrein and prostaglandin - May be classified into fore-,mid-, hind-gut tumours, 75-80% tumours include appendix and rectum, where they are often benign and non-secretory - Also found in other parts of large intestine, stomach, thymus, bronchus and other organs - Hormones released into the portal circulation are metabolised in the liver - Thus symptoms typically do not appear until there are hepatic metastases (resulting in the secretion of tumour products into the hepatic veins) or release into the systemic circulation from bronchial or extensive retroperitoneal tumours
3
Q
What is the epidemiology of carcinoid syndrome?
A
- Rare - Asymptomatic carcinoid tumours are more common and may be an incidental finding after rectal biopsy or appendectomy - 10% of patients with multiple endocrine neoplasia (MEN) type 1 have carcinoid tumours
4
Q
What are the presenting symptoms of carcinoid syndrome?
A
- Paroxysmal flushing - Diarrhoea - Crampy abdominal pain - Wheeze - Sweating - Palpitations
5
Q
What are the signs of carcinoid syndrome on examination?
A
- Facial flushing, telangiectasia, wheeze - Right sided heart murmurs: tricuspid stenosis, regurgitation or pulmonary stenosis - Nodular hepatomegaly in cases of metastatic disease - Carcinoid crisis: Profound flushing, bronchospasm, tachycardia and fluctuating blood pressure
6
Q
What are the investigations for carcinoid syndrome?
A
- 24h urine collection: 5-HIAA levels (a metabolite of serotonin, false positive with high intake of certain fruit/drugs e.g. bananas and avocados, caffeine, paracetamol - Blood: Plasma chromogranin A & B, fasting gut hormones - CT or MRI scan: To localises the tumour - Radioisotope scan: Radiolabelled somatostatin analogue (e.g. indum-111 octreotide) helps localise tumour - Investigations for MEN-1
7
Q
What are the investigations for carcinoid syndrome?
A
- 24h urine collection: 5-HIAA levels (a metabolite of serotonin, false positive with high intake of certain fruit/drugs e.g. bananas and avocados, caffeine, paracetamol - Blood: Plasma chromogranin A & B, fasting gut hormones - CT or MRI scan: To localises the tumour - Radioisotope scan: Radiolabelled somatostatin analogue (e.g. indum-111 octreotide) helps localise tumour - Investigations for MEN-1
8
Q
What are the signs of carcinoid syndrome on examination?
A
- Facial flushing, telangiectasia, wheeze - Right sided heart murmurs: tricuspid stenosis, regurgitation or pulmonary stenosis - Nodular hepatomegaly in cases of metastatic disease - Carcinoid crisis: Profound flushing, bronchospasm, tachycardia and fluctuating blood pressure
9
Q
What are the presenting symptoms of carcinoid syndrome?
A
- Paroxysmal flushing - Diarrhoea - Crampy abdominal pain - Wheeze - Sweating - Palpitations
10
Q
What is the epidemiology of carcinoid syndrome?
A
- Rare - Asymptomatic carcinoid tumours are more common and may be an incidental finding after rectal biopsy or appendectomy - 10% of patients with multiple endocrine neoplasia (MEN) type 1 have carcinoid tumours
11
Q
What is the aetiology of carcinoid syndrome?
A
- Carcinoid tumours are slow growing neuroendocrine tumours mostly derived from serotonin-producing enterochromaffin cells - They produce secretory products such as serotonin, histamine, tachykinins, kallikrein and prostaglandin - May be classified into fore-,mid-, hind-gut tumours, 75-80% tumours include appendix and rectum, where they are often benign and non-secretory - Also found in other parts of large intestine, stomach, thymus, bronchus and other organs - Hormones released into the portal circulation are metabolised in the liver - Thus symptoms typically do not appear until there are hepatic metastases (resulting in the secretion of tumour products into the hepatic veins) or release into the systemic circulation from bronchial or extensive retroperitoneal tumours
12
Q
What is carcinoid syndrome?
A
Constellation of symptoms caused by systemic release of humoral factors (biogenic amines, polypeptides, prostaglandins) from carcinoid tumours
