Chemical Pathology 6 - Adrenal Flashcards
Recall the 3 zones of the adrenal gland and what is produced in each one
Zone glomerulosa = aldosterone
Zona fasiculata = cortisol
Zona reticularis = androgens
What is Schmidt’s syndrome?
Well-known phenomenon in which primary hypothyroisidm presents alongside Addisson’s disease (primary adrenal failure)
What’s the test for Addisson’s, and how should it be performed?
SynACTHen test
Following adminstration of synthetic ACTH, check cortisol at 30 and 60 mins
What is the expected electrolyte abnormality in untreated primary adrenal failure?
Hyponatraemia, hyperkalaemia
What are the 3 differentials to consider when a patient with severe hypertension also has an adrenal mass?
- Phaeochromocytoma (medullary tumour)
- Conn’s syndrome (aldosterone-secreting tumour - zona glomerulosa)
- Cushing’s (zona fasciculata tumour secreting cortisol)
How should phaeochromocytoma be treated?
Alpha blockers (phenoxybenzamine) THEN beta blockers (to deal with reflex tachycardia)
What are the expected aldosterone and renin levels in untreated Conn’s syndrome?
High aldosterone, low renin
What are the expected aldosterone and renin levels in untreated Cushing’s syndrome?
Both low
What 3 tests can be used to investigate for Cushing’s?
- 9am cortisol
- Sneaky midnight cortisol (this is low when normal)
- Dexamethosone suppression test
What does the term ‘cushing’s disease’ refer to?
Cushing’s syndrome that is caused by a pituitary tumour secreting ACTH
What is the diagnosis in a patient with symptoms of Cushing’s but a normal result in the low-dose dexamethosone suppression test?
Normal obese person
What is the diagnosis in a patient with symptoms of Cushing’s but only a very slightly suppressed cortisol in the low-dose dexamethosone suppression test?
Cushing’s syndrome of indeterminate cause
How should Cushing’s syndrome of indeterminate cause be investigated?
Inferior petrosal sinus sampling with CRH stimulation
