Adrenal Disease Flashcards
Describe the adrenal microanatomy.
Capsule Adrenal cortex: - Zona glomerulosa - Zona fasciculata - Zona reticularis Adrenal medulla
Which hormones are produced by which zones of the adrenal cortex?
Zona glomerulosa = aldosterone (mineralocorticoids)
Zona fasciculata = cortisol (glucocorticoids)
Zona reticularis = androgens
What do wasted adrenal glands suggest?
Addison’s or long-term steroid treatment
What do hyperplastic adrenal glands suggest?
Cushing’s disease or ectopic ACTH
What is Schmidt syndrome?
Combination of autoimmune adrenal insufficiency (Addison’s) and primary hypothyroidism
How is Addison’s investigated?
Short SynACTHen test
Administer synthetic ACTH by IM injection
Check cortisol at 30 and 60 mins
Normal = produce > 550 nM of cortisol within 30 minutes
What would be seen in the urine of someone with a phaeochromocytoma?
High urine catecholamines
How is a phaeochromocytoma managed?
Urgent alpha blockade with phenoxybenzamine - leads to sudden drop in BP so can be given fluids beforehand
Give beta blocker to prevent reflex tachycardia
Surgery
What are genetic links of phaeochromocytomas?
MEN2
Von Hippel Lindau
Which tumours are seen in Von Hippel Lindau?
Phaeochromocytomas
Renal cell carcinoma
Renal cysts
Retinal/CNS haemangioblastoma
What does the biochemistry look like in Conn’s?
High sodium
Low potassium
High aldosterone
Low renin
What does the biochemistry look like in Cushing’s?
High sodium
Low potassium
Low aldosterone
Low renin
How is Cushing’s tested for?
Dexamethasone suppression test - should suppress cortisol
If a patient fails this test, then you sample the pituitary - 85% of the time, the cause is Cushing’s disease.
Common causes of Cushing’s syndrome
Oral steroids
Pituitary
Adrenal adenoma
Ectopic ACTH
