Chem Path: Adrenal disease Flashcards
Explain the microanatomy of the adrenals
From the outside:
- Capsule
- Glomerulosa making mineralocortocids
- Fasiculata making glucocorticoids
- Reticularis making sex steroids
- Medulla making adrenaline
What about the vasculature of the adrenals
Only 1 central vein but many arteries
Is cortisol a gluco or mineralocorticoid
Glucocortocid
How do the left and right adrenal veins drain
Left drains into left renal vein
Right drains into IVC directly
What is addison’s disease and how does it present?
Deficiency of aldosterone (low Na and high K) and glucocorticoid (Hypoglycaemia)
Addison’s + hypothyroidism is called what?
Schmidt’s syndrome / PGAI Type 2
How to test for Addison’s?
Synacthen test
How is it synacthen test done?
Measure cortisol and ACTH before injecting 250micro grams syActh my IM and see if cortisol rises
What do you use low dose dexa supp test for?
Cushings
What do you use glucose tolerance test for?
T2DM and 5 x GTT for acromegaly
What can cause Addison’s?
Autoimmune and TB
What are the 3 differentials for adrenal masses and how do they present?
Medulla - Phaechromocytoma - Excess adrenaline
Fasciculata - Cushings - Excess cortisol
Glomerulosa - Conns - Excess aldosterone
All present with hypertension and low K and high Na (less so for phaeo)
What can you see in the urine for people with adrenal masses?
Urinary catecholamines
What can phaeo cause?
Severe hypertension, cardiac arrhythmias and death
How to treat phaeo?
Alpha blockade
Remove tumour
How do you alpha blockade a patient for phaeo?
Phenoxybenzamine
What are some genetic associations with phaeo?
MEN 2, NF 1, VHL
How does Conns present
High Na, low K, hypertensive, raised aldosterone, low renin
What can cause Cushings syndrome
It is basically excess cortisol
Can be due to:
- Adrenal tumour
- Pituitary tumour producing ACTH
- Ectopic tumour producing ACTH
- Oral steroids
How do you test for Cushings
9 am cortisol
12 midnight cortisol
Dexa suppression test. - You are supposed to switch off ACTH and cortisol
How do you do a dexa test?
Measure ACTH and cortisol at the start
Give 0.5mg dexa every 6 to 48 hours
Cortisol should fall to <50nM
What is the difference between cushings syndrome and disease?
Syndrome - can be multiple causes
Disease - Pituitary DEPENDANT
How does Cushings present?
Hypertension, bruising, low K, high Na
What is pseudo-Cushings?
Obese people can present with high cortisol
How do you determine the cause of Cushings syndrome after dexa test
Pituitary sampling
