Carcinoid syndrome

Question 1

What is Carcinoid syndrome?

Answer 1

Constellation of symptoms (esp liver mets) caused by systemic release of humoral factors from carcinoid tumours
-Slow-growing type of neuroendocrine tumours

Question 2

Describe the aetiology of carcinoid syndrome

Answer 2

Mostly derived from serotonin-producing enterochromaffin cells (ileum)
Produce secretory products e.g. serotonin, histamine, tachykinins, kallikrein + prostaglandins
75-80% of pts with carcinoid syndrome have small bowel carcinoids

Question 3

Why are symptoms of carcinoid syndrome delayed?

Answer 3

Hormones released into the portal circulation will be metabolised by the liver so sx don’t tend to appear until there are hepatic mets or release into the systemic circulation from bronchial or extensive retroperitoneal tumours

Question 4

Describe the epidemiology of carcinoid syndrome

Answer 4

RARE
UK incidence : 1/1,000,000
Asymptomatic carcinoid tumours are more common
10% with MEN-1 have carcinoid tumours

Question 5

List 6 symptoms of carcinoid syndrome

Answer 5

Paroxysmal FLUSHING  
Diarrhoea  
Crampy abdominal pain  
Wheeze – due to bronchospasm  
Sweating  
Palpitations

Question 6

List 5 signs of carcinoid syndrome

Answer 6

Facial flushing
Telangiectasia
Wheeze
Right-sided murmurs (tricuspid stenosis/regurgitation or pulmonary stenosis)
Nodular hepatomegaly in cases of metastatic disease

Question 7

List 4 signs of carcinoid crisis

Answer 7

Profound flushing
Bronchospasm
Tachycardia
Fluctuating blood pressure

Question 8

What urine investigation may be performed in carcinoid syndrome?

Answer 8

24 hours urine collection

Check 5-HIAA levels (metabolite of serotonin) - elevated

Question 9

What blood tests may be performed in carcinoid syndrome?

Answer 9

High Plasma chromogranin A + B (reflects tumour mass)
High Serum serotonin
Gastrin (Fasting gut hormone)
Elevated Cr if dehydrated from diarrhoea

Question 10

What further investigations may be performed in carcinoid syndrome?

Answer 10

CT, MRI or PET: To localise the tumour

Somatostatin-receptor scintigraphy

Question 11

What is the most common site of primary tumour in carcinoid syndrome?

Answer 11

Appendix

Distal Ileum

Question 12

Name 2 cardiac signs of carcinoid syndrome

Answer 12

Tricuspid regurgitation
Pulmonary Stenosis
(primarily involves right side of heart)

Question 13

What is malabsorbed in carcinoid syndrome? What is the name for this? What symptoms does this produce if untreated?

Answer 13

Niacin
Pellagra
Diarrhoea, dermatitis + dementia

Question 14

What other syndrome may carcinoid syndrome present as?

Answer 14

Cushings syndrome

Question 15

Name 2 drugs used in treatment of carcinoid syndrome

Answer 15

Octreotide (somatostatin analogue): to block the release of tumour mediators
Alpha-interferon: to reduce tumour size + effects.