Adrenal Cortex and Medulla

Question 1

What are some of the golden rules of endocrinology

Answer 1

Think in diagnostic pairs
Hormone deficiency? = Stimulation test
Hormone excess? = Suppression test
Think, examine clinically, measure hormones then image

Question 2

What is primary adrenal failure (Addison’s Disease)

Answer 2

Adrenal itself damaged

ACTH high, low cortisol + aldosterone. Renin remain high

Question 3

What is secondary adrenal failure

Answer 3

Problem in hypothalamus/pituitary
ACTH & Cortisol low
Normal aldosterone + renin

Question 4

What is the danger of exogenous glucocorticoids

Answer 4

Taking tablets can shrink adrenals as it is not stimulated so once tablets taken off, go into acute adrenal crisis

Question 5

What cells release renin

Answer 5

Juxtoglomerular

Question 6

What is the action of mineralcorticoids on kidneys

Answer 6

Net Na+ resorption with K+/H+ loss

Question 7

What are the causes of Addison’s Disease

Answer 7

Autoimmune adrenalitis
TB
Congenital Adrenal hyperplasia
Adrenoleukodystrophy

NB: If Abs (-) & Male, measure V. Long chain fatty acid to exclude Adrenoleukodystrophy
If Abs + FA (-), CT adrenals to exclude TB

Question 8

What are the signs of adrenal insufficiency

Answer 8

Weight loss
Hyperpigmentation = In area’s with a lot of friction
Anaemic = Cortisol important in production of RBC
Hyponatraemia = Low serum Na
Hyperkalaemia = High serum K
Hypertension = especially postural

Question 9

How do you diagnose adrenal insufficiency

Answer 9

Low plasma cortisol that fails to respond to exogenous ACTH

Question 10

What is the treatment for adrenal insufficiency both acute and long term

Answer 10

Acute = IV Saline + Hydrocortisone
Long term = Replace glucocorticoids and mineralcorticoids
Sick Day Rule 1: Double oral hydrocortisone if inter-current illness with feber
Sick Day Rule 2: Inject hydrocortisone in major illness eg. trauma

Question 11

What is the difference between Cushings Syndrome/Disease

Answer 11

Syndrome = in general for too much glucocorticoid 
Disease = pituitary tumour that overproduces glucocorticoids

Question 12

How do you define Cushings

Answer 12

Constellation of symptoms and signs that reflect prolonged and inappropriately high exposure of tissue to glucocorticoids

Question 13

What are the causes of Cushings

Answer 13

Exogenous corticosteroids
Pituitary tumour
Adrenal adenoma/carcinoma
Ectopic ACTH syndrome eg. Small cell ling carcinoma

Question 14

What are the signs/symptoms of Cushings

Answer 14

Muscle dystrophy 
Striae in skin 
Central obesity 
Facial fullness 
Bruising due to thinning of skin

Question 15

How is Cushings diagnosed

Answer 15

24hr urinary free cortisol
Dexamethasone suppression test
Late night salivary cortisol. Cortisol should be undetectable
Measure ACTH to determine wether dependent or not
Pituitary or ectopic
Image

Question 16

How is Cushings treated

Answer 16

Surgery
Drugs
- Metyraprone = block adrenal enzymes so stop cortisol production
- Mitotaine = destroy adrenal tissue

Question 17

What are some of the effects of glucocorticoids on the system

Answer 17

Hypertension
Stop menstrual cycle + gonadal failure
Immunosuppression
Peripheral insulin resistance

Question 18

What is Conns disease

Answer 18

Primary aldosteronism

Characterised by hypertension & hyperkalaemia

Question 19

What are the causes of Conns disesase

Answer 19

Adrenal adenoma

Bilateral adrenal hyperplasia

Question 20

How do you diagnose Conns disease

Answer 20

Suppression of plasma renin activity

Question 21

How do you treat Conns disease

Answer 21

Surgery for adenoma
NB: Ineffective for hyperplasia
Drugs eg. Eplerenoma

Question 22

What is a phaeochromocytoma

Answer 22

Tumours of chromaffin tissue secreting NAd

So excess catecholamines

Question 23

What are the symptoms of phaeochromocytoma

Answer 23

Headache
Sweating
Palpitations

Question 24

What is the treatment for phaeochromocytoma

Answer 24

Alpha or beta blockers

Take out mass

Question 25

What is the difference between adenoma and carcinoma

Answer 25

Adenoma = benign. Fatty. Tumour density low.
Carcionoma = malignant. Not fatty
Larger tumours are more likely to be malignant

Question 26

What must you not do with phaeochromocytoma

Answer 26

Needle it as this will release catecholamines causing massive hypertension

Question 27

It is difficult to measure catecholamines, so what do we measure

Answer 27

Ad/NAd = short half lives

Broken into VMA which we measure

Question 28

In a case of adreno incidentaloma what do you have to think about

Answer 28

Exclude primary aldosteronism, cushings, adrenal androgen xs, phaeochromocytoma
Determine if malignant