262. Disorders of the adrenal gland

Question 1

Explain the layers of the adrenal cortex?

Answer 1

Zone Glomerulosa- aldosterone- affects sodium and potassium balance

Zona Fasciculata- cortisol- carbohydrate and lipid metabolism

Zona Reticularis- androgens

Question 2

What is Cushing’s syndrome?

Answer 2

Too much cortisol with loss of negative feedback

Question 3

What are the symptoms of cushing’s?

Answer 3

Increased weight 
low Mood 
proximal weakness
gonadal dysfunction
acne
achilles tendon rupture

Question 4

During CUSHING’s what signs are present?

Answer 4

Central obesity
Moon face
Skin and muscle atrophy
bruises
Raised BP and glucose

Question 5

What are the ACTH dependent causes of Cushing’s?

Answer 5

Cushing’s disease- Bilateral adrenal hyperplasia from ACTH secreting pituitary. 8mg dexmethasone may be enough to suppress morning cortisol

Ectopic ACTH production- occurs from a tumour e.g. small cell lung cancer. Dexmethasone wont suppress cortisol production

Question 6

What are the ACTH independent causes of Cushing’s?

Answer 6

Iatrogenic- Pharmacological doses of steroids

Adrenal adenoma/cancer

Adrenal nodular hyperplasia

Question 7

How do you investigate suspected Cushing’s?

Answer 7

1st line- overnight dexamethasone suppression test

2nd line- 48 hour dexamethasone suppression test

Localisation tests- scans, adrenal vein sampling, plasma ACTH

Question 8

How do you treat Cushing’s?

Answer 8

Stop medications if possible

Selective removal of pituitary adenoma

bilateral adrenalectomy

Question 9

What are the two types of adrenal insufficiency? (Addison’s)

Answer 9

Primary- Autoimmunity, TB, Adrenal mets, lymphoma

Secondary- Drugs, Hypothalmic pituitary disease

Question 10

What are the symptoms of addison’s

Answer 10

Very non-specific

Tanned, tired, tearful

Anorexia, dizzy, flu like symptoms

N+V, abdo pain, diarrhoea/constipation

Question 11

What tests can be done to investigate Addison’s?

Answer 11

Low sodium, high potassium,
Low glucose

Synacthen test- give ACTH and measure cortisol 30 mins later

Question 12

How is Addison’s disease treated?

Answer 12

Steroids replace- 15-25mg hydrocortisone daily
Avoid taking at night

minerealcorticoids 50-200mcg daily

Question 13

What do you need to advise those with Addison’s?

Answer 13

Wear bracelet that indicates steroid use
Double steroids when unwell
seek medical help if dehydrated

yearly BP and U&E review, watch out for autoimmune disease

Question 14

What is primary hyperaldosteronism?

Answer 14

Excess production of aldosterone independent of the renin-angiotensin system

Question 15

What are the signs and symptoms of hyperaldosteronism?

Answer 15

Often asymptomatic
First sign is hypokaelemia, may have hypernatremia also

Weakness, cramps, paraesthesia, polyuria, polydipsia. Raised BP but not always

Question 16

What are the causes of hyperaldosteronism?

Answer 16

2/3 due to aldosterone producing adenoma

Conn’s syndrome- bilateral adrenocortical hyperplasia

Question 17

What investigations are carried out in hyperaldosteronism?

Answer 17

Look for plasma renin and aldosterone

U&E’s

Adrenal vein samples

CT/MRI adrenals may show incedental finding and may complicate diagnosis

Question 18

How is hyperaldosteronism treated?

Answer 18

Conn’s adrenalectomy (not used for conn’s?) spironolactone pre-op

Spirolactone/amiloride treatment for hyperplasia

Question 19

What is secondary hyperaldosteronism?

Answer 19

Raised aldosterone and renin due to poor renal perfusion e.g. renal artery stenosis, accelerated hypertension, diuretics, CCF or hepatic failure

Question 20

What is Bartter’s syndrome?

Answer 20

Congenital defects in loop of Henle channels causing sodium loss. This increases renin and aldosterone production

Treatment is with potassium replacement, NSAIDS and ACE-I

Question 21

What is a phaechromocytoma?

Answer 21

Catecholamine producing tumour of the medullary cells

Often present with episodic headache, sweating and tachycardia

Question 22

What are the symptoms of pheochromocytoma’s

Answer 22

Symptoms may be precipitated by straining, exercise, stress, abdo pressure. Also B blockers, IV contrast and tricylcics may also cause symptoms to arise:

Heart:increased pulse, palpitations, dizziness, faints, cardiomyopathy

CNS: headache, visual problems, numbness, fits

Psychological: panic attacks, anxiety, episodic psychosis

Other:D&V, abdo pain, sweats/flsuhes. pallor, increased temp, backache

Question 23

How are pheochromocytoma’s tested for?

Answer 23

24 hour urine for ,etanephrines/metadrenaline (breakdown of catecholamines)

Abdo CT/MRI with chromaffin seeking isotope

Question 24

How do you treat a phaeochromocytoma?

Answer 24

Surgery: alpha blocker pre-op to stop adrenergic crisis

B blocker if heart disease or tachycardic

post op- 2 week later do 24 hours metanepherines