Disease

Question 1

What is the main cause of acromegaly?

Answer 1

90% = benign pituitary adenoma

Question 2

What is prognanthism?

Answer 2

Protusion of the mandible, seen in acromegaly

Question 3

What is Cushing’s syndrome?

Answer 3

A disease state caused by excess cortisol

Question 4

What is the most common cause of Cushing’s syndrome?

Answer 4

Exogenous steroids

Question 5

What is the most common endogenous cause of Cushing’s syndrome?

Answer 5

Pituitary adenoma

Question 6

What is Cushing’s disease?

Answer 6

Pituitary adenoma resulting excess cortisol production

Question 7

What are the causes of Cushing’s syndrome?

Answer 7

Exogenous steroids
Ectopic ACTH production
Adrenal adenoma/carcinoma
Pituitary adenoma

Question 8

Which causes of Cushing’s syndrome are due to excess ACTH?

Answer 8

Pituitary adenoma, ectopic ACTH secreting tumour

Question 9

Which causes of Cushing’s syndrome are due to corticosteroid excess and are not ACTH dependent?

Answer 9

Exogenous steroids, adrenal adenoma/carcinoma

Question 10

What is the role of low dose (1mg) dexamethasone suppression test?

Answer 10

Test for Cushing’s syndrome - if you administer dexamethasone and the morning cortisol is normal or high then Cushing’s syndrome is present

Question 11

What does it mean if a patient has low cortisol after a low dose dexamethasone suppression test?

Answer 11

They do not have Cushing’s syndrome

Question 12

What does it mean if a patient has normal cortisol after a low dose dexamethasone suppression test?

Answer 12

They have Cushing’s syndrome

Question 13

What does it mean if a patient has high cortisol after a low dose dexamethasone suppression test?

Answer 13

They have Cushing’s syndrome

Question 14

Why might you perform a 24 urinary cortisol?

Answer 14

To assess for Cushing’s syndrome

Question 15

What are the tests for Cushing Syndrome?

Answer 15

24 hour urinary cortisol, low dose dexamethasone suppression test, late night salivary cortisol

Question 16

What are the doses for the low and high dose dexamethasone tests?

Answer 16

Low = 1mg
High = 8mg

Question 17

What is the role of the high dose dexamethasone suppression test?

Answer 17

To differentiate causes of Cushing’s syndrome

Question 18

What does it mean if a patient has low cortisol after a high dose dexamethasone suppression test?

Answer 18

Pituitary adenoma - Cushing’s disease i.e. dexamethasone is sufficient to suppress the ACTH production

Question 19

What does it mean if a patient has high cortisol after a high dose dexamethasone suppression test?

Answer 19

The patient either has an ectopic ACTH producing tumour or an adrenal tumour or exogenous steroids

Question 20

How is ACTH level useful in differentiating between different causes of Cushing’s syndrome?

Answer 20

ACTH will be high in an ectopic tumour but low in an adrenal tumour

Question 21

What is Addison’s disease?

Answer 21

Adrenal insufficiency i.e. low cortisol

Question 22

What are the biochemical features of Addison’s disease?

Answer 22

Low sodium, Low sugar, Low BP

High Potassium, High Calcium, Metabolic acidosis

Question 23

Why do you see hyperpigmentation in Addison’s disease?

Answer 23

Increased ACTH production

Question 24

How commonly is hypertension caused by phaeochromocytoma?

Answer 24

0.1% of HTN cases are caused by phaeochromocytoma

Question 25

How does Conn's syndrome effect BP, potassium and sodium levels?

Answer 25

Low potassium Low BP High Sodium

Question 26

How does Addison's disease effect BP potassium and sodium levels?

Answer 26

High potassium High BP Low sodium

Question 27

How does Conn's syndrome effect BP?

Answer 27

Hypertension

Question 28

How does Addison's disease effect BP?

Answer 28

Hypotension

Question 29

What is the most common cause of primary hyperaldosteronism?

Answer 29

Bilateral idiopathic adrenal hyperplasia

Question 30

What is conn's syndrome?

Answer 30

Primary hyperaldosteronism caused by an adrenal adenoma

Question 31

What causes secondary hyperaldosteronism?

Answer 31

Caused by excess secretion of renin due to either renal artery stenosis or a renin secreting tumour

Question 32

Describe the biochemical features of addisons disease

Answer 32

Low mineralcorticoid = potassium retention and sodium and water loss, leading to high H+ ions and hypercalcaemia I.e high K+, low Na+, low BP, Metabolic acidosis, high Ca2+ Low glucocorticoid - low gluconeogenesis = hypoglycaemia

Question 33

What is the most common cause of Addison's disease?

Answer 33

Autoimmune adrenalitis leading to low production of glucocorticosteroid and mineralcorticosteroid

Question 34

What are the signs and symptoms of Addison's disease?

Answer 34

Muscle and joint pain, anxiety/personality change, hypotension, weight loss, hyperpigmentation

Question 35

Which types of adrenal insufficiency don't cause hyperpigmentation?

Answer 35

Secondary - low ACTH production from hypothalamus | Tertiary - low CRH production from hypothalamus

Question 36

Why is hyperpigmentation associated with Addison's disease?

Answer 36

Primary adrenal insufficiency leads to decrease in both mineralcorticosteroid and glucocorticosteroid production causing increased production of ACTH which causes hyperpigmentation

Question 37

What is the cause of congenital adrenal hyperplasia?

Answer 37

Deficiency in alpha 21-hydroxylase (in 90% of cases)

Question 38

What is the aetiology for congenital adrenal hyperplasia?

Answer 38

Autosomal recessive condition

Question 39

Which hormones are affected in congenital adrenal hyperplasia?

Answer 39

Deficiency in cortisol and aldosterone Excess androgen Excess ACTH

Question 40

What are the consequences of the hormone changes in congenital adrenal hyperplasia?

Answer 40

Deficiency in cortisol = increase in ACTH and hypoglycaemia Deficiency in aldosterone = low sodium, high potassium, hypotension Excess androgens in females result in virilisation, ambiguous genitalia Excess ACTH = adrenal hyperplasia

Question 41

What are the serum markers of congenital adrenal hyperplasia?

Answer 41

``` Hyperkalaemia Hyponatraemia Hypoglycaemia Raised 17-hydroxyprogesterone Raised androgens Reduced SHBG Reduced cortisol and aldosterone ```

Question 42

What are the clinical features of congenital adrenal hyperplasia?

Answer 42

``` Female virilisation (Irregular menses, ambiguous genitalia, short stature, acne, hirsutism) Hypotension ```

Question 43

Conns syndrome- what happens to the serum potassium

Answer 43

It is low (hypokalaemia)

Question 44

Congenital adrenal hyperplasia- what happens to serum potassium?

Answer 44

It increases (hyperkalaemia)

Question 45

Addison’s disease- what happens to the serum potassium?

Answer 45

It increases- hyperkalaemia

Question 46

Where do MEN type 1 tumours arise?

Answer 46

Pituitary gland, hyperparathyroidism, pancreas

Question 47

Where do MEN type 2 tumours arise?

Answer 47

Phaeochromocytoma, parathyroid hyperplasia, medullary cell carcinoma