Carcinoid Syndrome

Question 1

What is a carcinoid tumour. (2)

Answer 1

A diverse group of enterchromaffin cell (neural crest) origin tumours.
By definition, they are capable of producing 5HT.

Question 2

Where are common sites for carcinoid tumours. (4)

Answer 2

Appendix (45%).
Ileum (30%).
Rectum (20%).
Other places: GIT, ovary, testis, bronchi.

Question 3

What carcinoid tumours tend to metastasize.

Answer 3

80% of those >2cm across.

Question 4

What are the symptoms of carcinoid tumours. (4)

Answer 4

Initially few.
GI tumours may cause appendicitis, intussusception or obstruction.
Hepatic metastases may cause RUQ pain.
Tumours may secrete substances.

Question 5

What can carcinoid tumours secrete. (9)

Answer 5

Bradykinin. 
Tachykinin. 
Substance P. 
VIP. 
Gastrin. 
Insulin. 
Glucagon.
ACTH (Cushing's syndrome). 
Parathyroid and thyroid hormones.

Question 6

10% of carcinoid tumours are part of _____ syndrome.

Answer 6

MEN-1.

Question 7

10% of carcinoid tumours occur with other __________

Answer 7

neuroendocrine tumours.

Question 8

What is carcinoid syndrome.

Answer 8

It occurs in 5% of all carcinoid tumours and implies hepatic involvement.

Question 9

What are the signs and symptoms of carcinoid syndrome. (4)

Answer 9

Bronchoconstriction.
Paroxysmal flushing especially in upper body (and migrating weals).
Diarrhoea.
CCF (tricuspid incompetence and pulmonary stenosis from 5HT induced fibrosis).
Many CNS effects (eg enhanced ability to learn new stimulus-response associations).

Question 10

What will a 24h urine show in carcinoid syndrome.

Answer 10

Raised 5-HIAA.

Question 11

What is a carcinoid crisis.

Answer 11

When a tumour outgrown its blood supple or is handled too much during surgery, mediators flow out.

Question 12

What does carcinoid crisis cause.

Answer 12

Life threatening vasodilation, hypotension, tachycardia, bronchoconstriction and hyperglycaemia.