Tuesday, 14 September 2010

MRCP revision battle 11.5: Carcinoid Syndrome

Carcinoid tumours are common - 1% of the population will have one at post mortem.

They primarily secrete serotonin (5HT) but may also produce histamine/adrenal hormones/insulin...

45% of carcinoid tumours are in the appendix and a further 30% in the ileum.
They can cause complications such as appendicitis, obstruction or intussception.

Having said carcinoid tumours are common, it's important to understand that carcinoid syndrome is rare - it only occurs when the liver is involved, as tumours in other places will have their 5HT metabolised rather than it have an effect.

Features of carcinoid syndrome are:
  • flushing
  • diarrhoea
  • bronchospasm
  • pellegra
  • hypotension

Diagnosis is by:
  1. urinary 5-HIAA
  2. plasma chromograffin - the new way which, depending on the leve,  also gives an indication of the mass of tumours

Treatment is:
  • surgery
  • ocreotide

Survival from diagnosis tends to be 5 to 8 years.
Patients with carcinoid heart disease have a worse prognosis.

It is also worth remembering that if these tumours are over-handed (eg during surgery) or out-grow their blood supply, a massive 'hormone hit' can be released in one go, causing a carcinoid crisis.

Features of a carcinoid crisis:
  • vasodilation
  • hypotension
  • tachycardia 
  • bronchoconstriction
  • hyperglycaemia 

So those are today's battles fought, and hopefully won.  Click here if you want to partake of the 'war' of questions to check your recall of yesterday's topics.