Carcinoid Syndrome Flashcards
Define Carcinoid Syndrome
Constellation of symptoms caused by systemic release of humoral factors (serotonin 5-hydroxytryptamine) + biogenic amines, polypeptides, prostaglandins) from carcinoid tumours
Carcinoid tumour = slow-growing neuroendocrine tumours that produce secretory products
Aetiology Carcinoid Syndrome
Slow-growing neuroendocrine tumours mostly derived from serotonin-producing enterochromaffin cells -> produces serotonin, histamine, tachykinins, prostaglandins
75-80% - small bowel carcinoids
RF: MEN-1 syndrome
Hormones released into the portal circulation are metabolised in the liver -> symptoms do not appear until there are hepatic metastases or release into the systemic circulation
Symptoms of Carcinoid Syndrome
Diarrhoea Flushing (paroxysmal) - cutaneous e.g. face flushing Palpitations Abdominal cramps Wheeze Sweating
CARC: Cutaneous flushing Asthmatic wheeze Right sided murmur Cramps + diarrhoea
Signs of Carcinoid Syndrome on examination
Signs of RHF
Cardiac murmurs: tricuspid stenosis, regurgitation, pulmonary stenosis
Hepatomegaly
Abdominal masses
Telengiectasia
Pellagra (inflamed skin, diarrhoea, dementia, sores in the mouth)
Signs of carcinoid syndrome crisis
Profound flushing
Bronchospasm
Tachycardia
Fluctuating BP
Investigations for Carcinoid Syndrome
24-h urine collection for 5-HIAA levels: elevated
Plasma chromagranin A and B: elevated
Metabolic panel: elevated creatinine
LFTs: Variable, depends on site of tumours
FBC: usually normal
CT/MRI CAP: identifies primary tumours + metastases
Echo: Identify any valve pathologies
MIBG: Identifies areas of tumour through MIBG take-up
Biopsy: identify tumour type
Endoscopy: may find primary tumour
Stomatostatin receptor scintigraphy ± SPECT: identifies areas of somatostatin receptor-positive tumours