Carcinoid syndrome Flashcards
outline a typical presentation of carcinoid syndrome?
Facial flushing, right-sided murmurs, crampy pain, palp,D, bronchospasm, nodular hepatomegaly in mets, 5-HIAA (5-hydroxyindole acetic acid) levels high in 24hr urine , chromogranin A levels in blood
define carcinoid syndrome?
Constellation of symptoms (esp liver mets) caused by systemic release of humoral factors from carcinoid tumours (slow-growing type of neuroendocrine tumours)
explain the aetiology of carcinoid syndrome?
Carcinoid tumours are slow-growing neuroendocrine tumours
mostly derived from serotonin-producing enterochromaffin cells (ileum)
They produce secretory products like serotonin, histamine, tachykinins, kallikrein and prostaglandins
75-80% of patients with carcinoid syndrome have small bowel carcinoids
NOTE: hormones released into the portal circulation will be metabolised by the liver so symptoms don’t tend to appear until there are hepatic metastases or release into the systemic circulation from bronchial or extensive retroperitoneal tumours
give a risk factor for carcinoid syndrome?
genetic multiple endocrine neoplasia type 1 (MEN-1) syndrome
outline the epdemiology of carcinoid syndrome?
RARE
UK incidence : 1/1,000,000
Asymptomatic carcinoid tumours are more common
10% of patients with MEN-1 have carcinoid tumours
what are the presenting symptoms of carcnoid syndrome?
Paroxysmal FLUSHING
Diarrhoea
Crampy abdominal pain
Wheeze – due to bronchospasm
Sweating
Palpitations
what are the signs of carcinoid syndrome on physical examination?
Facial flushing
Telangiectasia
Wheeze
Right-sided murmurs (tricuspid stenosis/regurgitation or pulmonary stenosis)
Nodular hepatomegaly in cases of metastatic disease
what are the features of a carcinoid crisis?
Profound flushing
Bronchospasm
Tachycardia
Fluctuating blood pressure
what are the appropriate investigations for carcinoid syndrome?
24 hours urine collection -> Check 5-HIAA levels (metabolite of serotonin) - elevated
Blood
- Plasma chromogranin A and B – elevated
- Neuron spec enolase (NSE)
- Substance P
- Gastrin (Fasting gut hormones)
- Elevated Cr if dehydrated from diarrhoea
- LFTs-> variable, changes include aminotransferase elevation depending on site of tumour
CT or MRI Scan or PET scan-> To localise the tumour
Radioisotope Scan
- Radiolabelled somatostatin analogue helps localise the tumou