Adrenal Pathology Flashcards
What is the venous drainage of the left adrenal gland?
Left adrenal vein -> left renal vein -> IVC
What is the venous drainage of the right adrenal gland?
Right adrenal vein -> IVC
What are the 3 regions of the adrenal cortex?
Zona Glomerulosa
Zona Fasiculata
Zona Reticularis
What types of substances does the Zona Glomerulosa produce?
Mineralocorticoids like Aldosterone
What types of substances does the Zona Fasiculata produce?
Glucocorticoids like cortisol
What types of substances does the Zona Reticularis produce?
Sex hormones like DHEA and androstenedione
What controls mineralocorticoid production like aldosterone from the zona glomerulosa?
RAAS system producing Renin
What controls glucocorticoid production like cortisol from the zona fasiculata?
ACTH control from the anterior pituitary gland
What controls sex hormone production like DHEA and Androstenedione from the zona reticularis?
ACTH by the anterior pituitary gland
What are the 2 types of adrenal insufficiency?
Primary adrenal insufficiency
Secondary adrenal insufficiency
What is primary adrenal insufficiency?
Where there are issues with the adrenal glands themselves
What is secondary adrenal insufficiency?
Where there is an issue with the pituitary gland producing ACTH
What is the most common cause of primary adrenal insufficiency?
Addisons disease (autoimmune)
What are some causes of primary adrenal insufficiency?
Addisons (autoimmune)
Infiltration (sarcoidosis, Amyloidosis)
Infection (TB,HIV)
Infarction
Congenital
Iatrogenic
What are some congenital causes of primary adrenal insufficiency?
Congenital Adrenal Hyperplasia (CAH)
Triple A syndrome
What is the pathophysiology of congenital adrenal hyperplasia?
Deficiency of 21-hydroxylase enzyme
What is an iatrogenic cause of primary adrenal insufficiency?
Bilateral Adrenalectomy
What is the most common cause of secondary adrenal insufficiency?
AXIS SUPPRESSION VIA EXOGENOUS CORTICOSTEROIDS
With primary adrenal insufficiency, what hormones are affected/reduced?
All corticosteroid hormones :
-aldosterone
-cortisol
-DHEA and androgenestione
What hormones are reduced in secondary adrenal insufficiency?
Cortisol
DHEA and androgenestione
ALDOSTERONE IS FINE SINCE CONTROLLED BY RAAS SYSTEM BUT CORTISOL AND SEX HORMONES LOW SINCE RELY ON ACTH FROM PITUITARY
What is an alternate name for primary adrenal insufficiency?
Addisons disease
How does primary adrenal insufficiency/addisons disease present?
Hyperpigmentation
Anorexia
Weight loss
Tiredness
Weakness
Dizziness
Postural hypotension
Reduced libido/pubic hair
Vomiting
Why does primary adrenal insufficiency cause hyperpigmentation of the skin?
Pituitary produces lots of ACTH to try and increase corticosteroid hormone levels of glucocorticoids and sex hormones
By product of producing ACTH is MSH (melanocytes stimulating hormone)
How does secondary adrenal insufficiency present?
Almost identical to primary BUT NO HYPERPIGMENTATION
Why is there no skin hyperpigmentation with secondary adrenal insufficiency?
Secondary adrenal insufficiency caused by pituitary not producing enough ACTH leading to under active adrenal glands
Low ACTH means low levels of MSH
What investigations would you request if you think a patient might have adrenal insufficiency?
FBC
U+Es
9am cortisol
Short SynACTHen test (stimulation test)
ACTH levels
Adrenal cortex and 21-hydroxylase autoimmune antibodies
CT / MRI adrenals not always needed or MRI pituitary
What electrolyte abnormalities can be seen with adrenal insufficiency?
HYPONATRAEMIA (most common)
Hyperkalaemia
Hypoglycaemia
Hypercalcaemia
Elevated creatinine and urea (Dehydration)
Once adrenal insufficiency has been identified via a low 9am cortisol and a significant short SynACTHen test, how do you determine primary or secondary adrenal insufficiency?
Measure serum ACTH levels
If ACTH levels high = Primary adrenal insufficiency
If ACTH levels low = Secondary adrenal insufficiency
How is adrenal insufficiency managed?
Glucocorticoid replacement = Hydrocortisone BD or TDS (20-30mg per day so dose spilt with larger dose being in the morning)
Mineralocorticoid replacement = fludrocortisone (50-300mg daily)
Sick day rules, STEROID CARD/WRIST BAND and emergency pack
What are the sick day rules?
Patient taking any corticosteroids must double the dose of their steroids when they are ill
Emergency IM hydrocortisone can be given if needed
What is an adrenal or Addisonian crisis?
An acute presentation of a severe adrenal insufficiency caused by life threatening low levels of corticosteroids
How can a patient present with an adrenal/addisonian crisis?
Hypotension / vascular collapse
Reduced consciousness
Hypoglycaemia
Abdominal pain
Tachycardia
Hyponatraemia + Hyperkalaemia
When a patient has acutely deteriorated, when would you suspect an adrenal crisis/addisonian crisis?
Cortisol suspected low when:
-resistant to fluid resuscitation
-resistant metabolic acidosis
How do you diagnose an adrenal / addisonian crisis?
Cortisol levels
Plasma ACTH
Blood gas
Short SynACTHen
What is the immediate emergency management of an adrenal/addisonian crisis?
100mg IV bolus hydrocortisone
Then continous IV infusion of 200mg Hydrocortisone over 24hrs OR 6hrs doses of 50mg Hydrocortisone
Fluid resuscitation + dextrose if. Hypoglycaemic
Treat underlying causes
?calcium gluconate if hyperkalaemia
What causes an adrenal/addisonian crisis?
Infections
Sepsis
Major stress like surgery
What are the 2 types of Hyperaldosteronism?
Primary Hyperaldosteronism
Secondary Hyperaldosteronism
What is primary Hyperaldosteronism?
When the adrenal glands are producing too much aldosterone without being stimulated by renin
What is secondary Hyperaldosteronism?
When there are very high levels of renin in the body leading to high levels of aldosterone being produced
What is the function of aldosterone?
Inc sodium reabsorption in kidneys
Inc potassium loss in kidneys
Inc hydrogen secretion from collecting duct
How does the RAAS lead to the production of aldosterone?
Juxtaglomerular cells make renin
Renin converts Angiotensinogen to Angiotensin I, ACE converts Angiotensin I to angiotensin II which leads to prodcution of aldosterone
How does a patient with Hyperaldosteronism present?
Resistant HTN
Hypokalaemia
Alkalosis (excess H+ secretion)
What is resistant hypertension?
On 3 or more anti-HTN medications without the HTN resolving
What are the causes of primary Hyperaldosteronism?
Bilateral adrenal hyperplasia
Conns syndrome (adenoma making aldosterone)
What are some causes of secondary Hyperaldosteronism?
Renal tubular acidosis
Heart. Failure
Renal artery stenosis
Liver cirrhosis and ascites
What is essential HTN?
HTN that runs int he family and the cause isn’t known
What is secondary HTN?
HTN with a known cause
What are some causes of secondary HTN?
Renal artery stenosis
Glomerulonephritis
Conns syndrome
Cushings
Hyperparathyroidism
What investigations would you do for a primary Hyperaldosteronism?
U+Es (low sodium and high potassium)
ABG or VBG (Alkalosis)
Aldosterone to Renin Ratio
CT/MRI adrenals
Venous sampling
Saline infusion and fludrocortisone suppression test
How can you differentiate between primary and secondary Hyperaldosteronism?
ALDOSTERONE TO RENIN RATIO
What would the aldosterone to renin ratio be for a patient with primary Hyperaldosteronism?
High aldosterone to renin ratio
Low renin
High aldosterone
What would the aldosterone to renin ratio be for a patient with secondary Hyperaldosteronism?
Normal/low aldosterone to renin ratio
High renin
High aldosterone
What is the management for Hyperaldosteronism?
Treat underlying cause.
Laparoscopic Adrenalectomy
Mineralocorticoid receptor antagonists like Spironolactone (bilateral adrenal hyperplasia)
GRA treated with low dose dexamethasone
What is adrenal Cushing’s syndrome?
Too much cortisol made by the adrenals independant to ACTH
What are the 2 main causes of adrenal Cushing’s syndrome?
Adrenal adenoma
Adrenal carcinoma
How does adrenal Cushing’s syndrome present?
Weight gain
Plethoric moon shaped face
Buffalo hump
Purple striae
Central adiposity
Proximal limb muscle wastage
What are the signs of adrenal Cushing’s syndrome?
HTN
T2DM
Osteoporosis
Recurrent infections
Dyslipidaemia
Anxeity
Depression
What investigations need to be done to diagnose adrenal Cushing’s syndrome?
Any 2 abnormal from:
-midnight cortisol
-urine cortisol
-salivary cortisol
-low dexamethasone suppression test
-high dose dexamethasone suppression test
ACTH levels
Venous sampling
CT adrenals
How do you treat an adrenal Cushing’s caused by an adrenal adenoma?
Unilateral Adrenalectomy + Steroid cover
What is the management for adrenal Cushing’s caused by bilateral adrenal hyperplasia?
MDT meeting
Either medical management or bilateral Adrenalectomy with steroid replacement
What medication can be given to treat adrenal Cushing’s?
Metyrapone
What is Phaeochromocytoma?
Neuroendocrine tumour originating from the adrenal medulla producing Catecholamines like adrenaline and noradrenaline
What cells normally produce Catecholamines like adrenaline?
Chromaffin cells
What genetic conditions are associated with Phaeochromocytoma?
MEN2
Neurofibromatosis 1
VHL (Von hippel Lindau)
How does a patient with Phaeochromocytoma present?
Resistant HTN
Palpitations
Headaches
Sweating
Anxiety
Flushing
Tremor
Tachycardia
What are some complications of Phaeochromocytoma?
HF
Cardiomyopathy
Pulmonary oedema
What can precipitate and episode of Phaeochromocytoma?
Stress
Exercise
Pressure on the abdomen
Surgery
Drugs (anaesthetics, B blockers, contrast)
How should you investigate a Phaeochromocytoma?
24hr urine Catecholamines/metanephrines
Plasma free metanephrines
CT/MRI
Screening for associated. Conditions (MEN, VHL, NF1)
How do you manage a Phaeochromocytoma?
Alpha blockers first = phenoxybenzamine or doxazosin
Beta blockers after settled on alpha blockers
Then surgical resection once stable
