19. Adrenal Disorders Flashcards
What are the 3 layers of the adrenal cortex from outside in and what do they secrete?
Zona glomerulosa - mineralocorticoids
Zona fasiciculata - glucocorticoids
Zona reticularis - androgens
What is the clinical presentation of cortisol deficiency?
Weakness
Tiredness
Weight loss
Hypoglycaemia
What is the clinical presentation of a mineralocorticoid (aldosterone) deficiency?
Dizziness
Low Na
High K
What is the clinical presentation of an androgen deficiency?
Low libido
Loss of body hair in women
What is the clinical presentation of a cortisol excess?
Weight gain and cushingoid features
What is the clinical presentation of mineralocorticoid excess?
High BP and low K
What is the clinical presentation of androgen excess?
Increased male characteristics in women
What is the clinical presentation of ACTH excess from pituitary?
Skin pigmentation melanocyte stimulation
What is the presentation of excessive catecholamine secretion?
Acute episodes Sweating Anxiety Palpitations High or low BP Collapse Sudden death
What will the biochemical assessment show if suspected adrenal hormone deficiency?
Electrolytes - low Na, (high K in aldosterone deficiency)
0900 basal cortisol - low
Stimulation test
What will the biochemical assessment show if suspected adrenal hormone excess?
Electrolytes - high BP, low K Midnight cortisol - high 24hr urine cortisol - high Suppression test - failure to suppress Androgens and derivatives - high
What foods should be avoided before a biochemical assessment of adrenal medulla?
Coffee Coke Bananas Chocolate Vanilla
What are the catecholamines in the 24 hr urine?
Adrenaline
Noradrenaline
Dopamine
3-methoxy-tyramine
What is primary adrenal failure (Addison’s disease) mainly due to?
Auto-immune disease
What are the symptoms of Addison’s disease?
Fatigue Weakness Anorexia Weight loss Nausea Abdominal pain Dizziness Pigmentation
What are the signs of Addison’s disease?
Underweight Signs of weight loss General malaise Other auto-immune diseases - vitiligo, thyroid Postural hypotension Pigmentation
What are the causes of primary adrenal failure?
Auto-immune Infection - TB, fungal, AIDS Infiltration - amyloid, haemochromatosis Malignancy - lung, breast, kidney Genetic - CAH, adreno-leukodystrophy
What are the clinical features of adrenal crisis?
Collapse Hypotension Dehydration Pigmentation Coma
What do the blood tests in adrenal crisis show?
Low sodium High potassium High urea High creatinine Low cortisol levels
What is the initial treatment of adrenal crisis?
Rapid rehydration with fluids
IV hydrocortisone
Correction of hypoglycaemia
Search for precipitating cause
What is the maintenance treatment of Addison’s disease?
Lifelong replacement
- glucocorticoid (hydrocortisone, prednisolone)
- mineralocorticoid (fludrocortisone)
What is the difference in results between ACTH deficiency and primary adrenal failure?
in ACTH deficiency:
No pigmentation as ACTH not raised
No hyperkalaemia as no mineralocorticoid deficiency
Hyponatraemia due to effect of cortisol on free water excretion
What is Cushing’s syndrome?
Glucocorticoid excess
What are the signs and symptoms of Cushing’s syndrome?
Round pink face with round abdomen Skinny and weak arms and legs Thin skin and easy bruising Red stretch marks on abdomen High BP and diabetes Osteoporosis
What are the causes of Cushing’s syndrome?
Pituitary tumour
Adrenal tumour
Ectopic ACTH
Patients taking steroids
Why do the arms and legs become thinner in Cushing’s syndrome?
Excess cortisol causes lipolysis and break down of protein in muscle
What is adrenal Cushing’s syndrome?
Adrenal tumour secreting glucocorticoids
May also secrete cortisol metabolites
What is the presentation of adrenal Cushing’s syndrome?
ACTH is suppressed
Androgenic symptoms may be present - hirsutism, acne, greasy skin
Virilising features in large tumours - androgenic alopecia, deep voices, clitoromegaly
What is the treatment for adrenal Cushing’s syndrome?
Adrenalectomy
What is the risk after an adrenalectomy?
Post-op hypoadrenalism risk due to contra-lateral adrenal suppression
What is primary hyperaldosteronism?
Excess production of aldosterone from adrenal gland
What is Conn’s syndrome?
Aldosterone-secreting adrenal adenoma
What is the commonest form of endocrine hypertension?
Primary hyperaldosteronism
What does primary hyperaldosteronism cause?
Hypertension and hypokalaemia
High aldosterone and suppressed renin
Scan shows adrenal adenoma or bilateral hyperplasia
How is Conn’s adenoma treated?
Surgery
How is bilateral hyperplasia treated?
Aldosterone antagonists - spironolactone/eplerinone
What is congenital adrenal hyperplasia?
Autosomal recessive
Adrenal crisis and ambiguous genitalia
Caused by a block in adrenal cortex pathway
Presentation depends on enzyme defect
What does the lack of enzyme in congenital adrenal hyperplasia lead to?
Low cortisol and aldosterone
High male hormone (androgens)
Which enzyme is most commonly absent in congenital adrenal hyperplasia?
21-hydroxylase
What is the presentation of congenital adrenal hyperplasia?
Hypotension Hyponatraemia Hyperkalaemia Hypoglycaemia Virilisation
What is the treatment of congenital adrenal hyperplasia?
Treat adrenal crisis
Determine sex of baby
Long term GC and MC
Corrective surgery
What is phaeochromocytoma?
Tumour of adrenal medulla
What is paraganglioma?
Extra-adrenal tumour- chromaffin tissue origin
What are the symptoms of phaeochromocytoma and paraganglioma?
Acute episodes Sweating Panic attacks Palpitations High or low BP Collapse
What happens in acute crisis of phaeochromocytoma and paraganglioma?
Hypertensive crisis Encephalopathy Hyperglycaemia Cardiac arrhythmias Sudden death
What are the investigations needed for phaeochromocytoma and paraganglioma?
24hr urine metanehrines
2-3 collections needed
Plasma metanephrines
What is the management for phaeochromocytoma and paraganglioma?
Alpha blockade - phenocybenzamine
Beta-blockade - bisoprolol
Surgical excision
