Carcinoid Syndrome Flashcards
what is the def of CS
a group of associated symptoms caused by release of humoral factors (biogenic amines, polypeptides, prostaglandins) from carcinoid tumours
what are carcinoid tumours
slow growing neuroendocrine tumours
what is the aetiology of CS
carcinoid tumours are slow growing neuroendocrine tumours mostly derived from serotonin-producing enterochromaffin cells
produce secretory products such as serotonin, histamine, prostaglandins
can be classified into fore-, mid- or hindgut tumours
75-80% of CS patients have small bowel carcinoids
common sites for carcinoids tumours are include appendix & rectum where they are benign & non-secretory
hormones released into portal circulation are metabolised by liver therefore symptoms do not appear until there are hepatic metastases (resulting in secretion of tumour products into the hepatic veins).
what is the epi of CS
rare
asymptomatic carcinoid tumours are more common
10% of multiple endocrine neoplasia (MEN) type 1 patients have carcinoid tumours
what history is associated with CS
paroxysmal flushing diarrhoea crampy abdominal pain wheeze sweating palpitations
what examinations findings are associated with CS
facial flushing, telangiectasia (broken capillaries), wheeze
RS heart murmurs
-tricuspid stenosis, regurgitation or pulmonary stenosis
nodular hepatomegaly in cases of metastatic disease
what examination findings are associated with carcinoid crisis
profound flushing
bronchospasm
tachycardia
fluctuating BP
what investigations would be performed in suspected CS
24h urine collection
-5-HIAA levels (a metabolite of serotonin)
bloods
-plasma chromogranin A & B, fasting gut hormones
radioisotope scan
-radiolabelled somatostatin analogue to localise tumour
what are the causes of high 5-HIAA (false positives)
bananas & avocados
caffeine
paracetamol
