Carcinoid Tumours & Syndrome Flashcards
What are carcinoid tumours?
A diverse group of tumours of enterochromaffin cell origin (neural crest), by definition capable of producing 5HT.
Common sites of carcinoid tumours.
Appendix (45%)
Ileum (30%)
Rectum (20%)
They can also occur elsewhere in the GI tract such as ovary, testis and bronchi.
80% of tumours larger than 2 cm will metastasise.
Clinical features or carcinoid tumours.
Initially few.
GI tumours can cause - appendicitis, intussusception or obstruction.
Hepatic metastases may cause RUQ pain
Tumours may secrete bradykinin, tachykinin, substance P, VIP, gastrin, insluin, glucagon, ACTH, parathyoroid and thyroid hormones.
What is carcinoid syndrome?
Occurs in 5% of all carcinoid tumours.
It implies hepatic involvement
Symptoms and signs of carcinoid syndrome.
Bronchoconstriction
Paroxysmal flushing especially in upper body.
Diarrhoea
CCF
Carcinoid crisis
Explain carcinoid crisis.
When a tumour outgrows its blood supply or is handled too much during surgery.
This leads to mediators flood out.
This causes life-threatening vasodilation, hypotension, tachycardia, bronchoconstriction and hyperglycaemia.
Treatment of carcinoid crisis.
High dose octreotide (mimics somatostatin causing inhibition of growth hormone, glucagon, and insulin etc…)
Supportive measures
Careful management of fluid balance vie a central line.
Investigations of carcinoid syndrome.
24h urine 5-hydroxyindoleacetic acid.
CXR + chest/pelvis
MRI/CT
Plasma chromogranin A
Indium octreotide scintigraphy (octreoscan)
PET scan
Treatment of carcinoid syndrome.
Octreotide (somatostatin analogue) which blocks the release of tumours mediator and counters peripheral effects.
Lanreotide is a long-acting alternative.
Loperamide for diarrhoea
Carcinoid tumour therapy.
Resection is the only cure, which means it is essential to find the primary site.
Can be resected endoscopically.
