W9 - Adrenal disease Flashcards
which adrenal zone makes cortisol?
Zona Fasciculata
Which adrenal zone makes aldosterone?
Zona glomerulosa
Which adrenal zone makes androgens? Which is the most important hormone it makes?
Zona reticularis
DHEA
Which adrenal zone makes the fight or flight hormones? Name these hormones
Adrenal medulla - catecholamines (epinephrine, norepinephrine)
What is this histology section?
Identify the main parts (6)
- Medulla
- Reticularis
- Fasciculata
- Glomerulosa
- Capsule
- Periadrenal fat
Adrenal histology
Describe vasculature of adrenal gland
Many arteries supply the adrenal gland, such as suprarenal artery
ONLY ONE vein drains the adrenal gland
- 31 year old presents with profound tiredness.
- Acutely unwell a few days.
- Vomiting
Test results:
Na: 125, K: 6.5, U 10, Glucose 2.9mM.
FT4 < 5nM TSH > 50mU/l
=> What does this TSH suggest?
A. A TSH producing pituitary adenoma
B. Graves disease
C. A toxic thyroid nodule
D. Primary hypothyroidism
E. de Quervain’s (viral) thyroiditis.
Is that the only disease?
D. primary hypothyroidism
A explanation: the TSH will go just a bit up and then they’ll feel very sick. But TSH levels will not reach this level!
- Hypothyroidism does NOT explain the unusual electrolytes:
- Na: 125, K: 6.5, U 10 => suggest deficiency of a mineralocorticoid
- Glucose 2.9mM => hypoglycaemis suggests deficiency of a glucocortoid
= hence, Addison’s!
Schmidt’s syndrome - what is it? Another name for it
Primary hypothyroidism AND Addison’s disease
aka Autoimmune polyglandular syndrome type 2
What test would you do for Addison’s?
synACTHen test!
What test would you do for Cushing’s syndrome?
Low dose dexamethasone suppression test (LDDST)
Describe how short SYNACTHEN test is performed
- Measure cortisol + ACTH at start of the test
- Administer 250 micrograms synthetic ACTH (IM)
- Measure cortisol at 30 min and 60 min
Short SYNACTHEN test results:
- Initial: ACTH > 100 ng/dl, Cortisol < 10 nM
- Cortisol at 30 and 60 minutes => both times, cortisol < 10 nM
What do these results suggest? What are the common causes (2)?
Cortisol bascially undetectable therefore:
adrenal failure - common causes:
- Autoimmune adrenal failure = Addison’s disease
- Tuberculosis-infiltrated adrenal failure
- A 32 year old presents with hypertension.
- He is noted to have an adrenal mass.
What are the three possible differentials?
- Phaechromocytoma - adrenal medullary tumour secreting adrenaline
- Conn’s disease - adrenal tumour secreting aldosterone
- Cushing’s disease -secreting cortisol
- A 32 year old presents with hypertension.
- He is noted to have an adrenal mass.
- Further investigations reveal that he has high levels of urinary catecholamines.
Describe management of this patient
Phaechromocytoma
- Alpha blockade with phenoxybendamzine - BP control
- Beta blockade - symptom control (HR down)
- Adrenalectomy
What is phaechromocytoma? Symptoms it can cause
- adrenal medullary tumour secreting catecholamines (adrenaline)
- severe hypertension, arrhythmias, and death
Which tests can be used for phaechromoctyoma?
- Urinary catecholamines
- plasma free metanephrines
- Hypertensive 33 year old.
- Na 147, K 2.8, U 4.0. Glucose 4.0 mM. Plasma aldosterone raised. Plasma renin suppressed.
What is the diagnosis ?
hypernatraemic, hypokalaemic, high aldosterone => CONN’S SYNDROME (primary hyperaldosteronism)
- 34 year old obese woman with type 2 diabetes, presents with hypertension and bruising.
- Na: 146, K: 2.9, U 4.0, Glucose 14.0. Aldosterone <75 (low). Renin low
TRUE or FALSE: This excludes Conn’s and suggests another hormone is causing the hypertension.
True = no aldosterone = no hyperaldosteronism
•34 year old obese woman with type 2 diabetes, presents with hypertension and bruising.
What is the diagnosis?
Cushing’s syndrome
What tests (3) would you order for Cushing’s syndrome?
- 9 am cortisol
- 12 midnight cortisol
- Low dose dexamethasone suppression test
* in that order (1 => 2 => 3)
What are the causes (4) of Cushing’s syndrome, from most likely to least likely
- Being on steroids for something else
- Pituitary-dependent Cushing’s DISEASE (85%)**
- Adrenal adenoma (10%)
- Ectopic ACTH (5%)
** these %s come from when patient is NOT on steroids
An obese 35 year old patient has the following results:
- 9am cortisol (Monday): 650 nM
- Given 0.5 mg dexamethasone every 6 hours for 48 hours
- 9am cortisol (Wednesday) < 50nM
What is the diagnosis? What should be done next?
Properly suppressed - nothing wrong with her cortisol response. She is a NORMAL obese person.
*her cortisol may have been high initially because 1) she’s stressed, 2) she’s obese.
- 9am cortisol (Monday): 650 nM
- Given 0.5 mg dexamethasone every 6 hours for 48 hours
- 9am cortisol (Wednesday) 500nM
A) What is the diagnosis?
B) What should be done next ?
A) Cushing’s syndrome of indeterminate cause - it may be:
- pituitary dependent cushing’s disease
- Adrenal tumour causing Cushing’s syndrome
- Ectopic ACTH causing Cushing’s syndrome
B) Sampling from the pituitary (IPSS with CRH stimulation)
If patient has Cushing’s disease of indeterminate cause - what is the best test to do and why?
A. Pituitary MRI
B. Adrenal CT scan
C. Chest X-ray to look for an ectopic source
D. Tell her she does not have any serious adrenal problem
E. High dose dexamethasone suppression test
F. Sampling from the pituitary (IPSS)
F is the best test to do
A) about 20% of people have a non-functioning pituitary mass so it might show a mass, but it won’t be the reason for the Cushing’s
B) rarer cause
C) insensitive, rarer cause
D) –
E) this will just confirm a diagnosis of Pituitary dependent Cushing’s disease -> surgeon will take out pituitary, then turns out it’s another cause so it’s a redundant test.
