Multiple endocrine neoplasia

Question 1

Define multiple endocrine neoplasia

Answer 1

Autosomal dominant condition characterised by predilection to develop tumours of endocrine glands

Question 2

Aetiology of multiple endocrine neoplasia (general + 3 types)

Answer 2

Autosomal dominant inheritance

MEN 1
MEN 2a
MEN 2b

Question 3

Aetiology of multiple endocrine neoplasia - MEN 1

4

Answer 3

Pituitary adenomas
Parathyroid tumours
Pancreatic islet-cell tumours (& other endocrine tumours of the gastroenterohepatic tract e.g. gastrinomas)
Fascial angiofibromas & collagenomas

Question 4

Aetiology of multiple endocrine neoplasia - MEN 2a

3

Answer 4

Parathyroid tumours
Medullary thyroid cancer
Phaeochromocytomas

Question 5

Aetiology of multiple endocrine neoplasia - MEN 2b

3

Answer 5

Same as MEN 2a
Marfanoid appearance
Neuromas of GI tract

Question 6

Epidemiology of multiple endocrine neoplasia

prevalence

Answer 6

VERY RARE

Question 7

Presenting symptoms & signs of multiple endocrine neoplasia - MEN 1
(5)

Answer 7

Age of onset of tumours is usually teenage years
Symptoms of tumours may not become apparent for years
Diagnosis commonly made in 4th decade of life
Symptoms & signs dependent on organs affected
Pituitary tumour may cause visual defects

Hyperparathyroidism —> symptoms of hypercalcaemia + nephrolithiasis
Hypergastrinaemia —> Zollinger-Ellison syndrome
Hyperinsulinaemia —> hypoglycaemia
Hyperprolactinaemia —> amenorrhoea
Hypersomatotrophinaemia —> acromegaly

Question 8

Presenting symptoms & signs of multiple endocrine neoplasia - MEN 2
(3)

Answer 8

Symptoms of medullary thyroid cancer, hyperparathyroidism or phaeochromocytoma

Medullary thyroid cancer symptoms
hypertension 
episodic sweating 
diarrhoea 
pruritic skin lesions
lump in neck

Hypercalcaemia symptoms 
constipation
polyuria/polydipsia
depression
kidney stones
fatigue

Question 9

Investigations for multiple endocrine neoplasia - MEN 1

3

Answer 9

Screening 1st/2nd degree relatives
Hormone hypersecretion blood tests
DNA testing

Question 10

Investigations for multiple endocrine neoplasia - MEN 2

3

Answer 10

Phaeochromocytoma test - 24hr urine metanephrines (can be followed by abdo MRI)
Medullary thyroid cancer test - elevated calcitonin concentration (can also be investigated w/ US & FNA)
Parathyroid tumours - simultaneous elevated Ca2+ & PTH