Adrenal Disease Flashcards
What is Cushing’s syndrome?
Symptoms of increased circulating glucocorticoid
What are the common causes of Cushing’s?
Exogenous administration of steroids Increased ACTH -pituitary (65%) -ectopic (15%) Excess adrenal cortisol -adrenal tumour/nodular hyperplasia (25%) -subsequent ACTH suppression
What are the symptoms of Cushing’s?
Central weight gain Change of appearance Depression Insomnia Poor libido Thin skin/easy bruising Excess hair growth/acne Sx of DM
What are the signs of Cushing’s?
Moon face Frontal balding Striae Hypertension Pathological fractures Dorsal fat pad (buffalo hump) Proximal myopathy
How is Cushing’s diagnosed?
Raised cortisol
Overnight dexamethasone suppression test
Plasma ACTH
Describe the overnight dexamethasone suppression test
1mg oral dexamethasone given at midnight
Serum cortisol checked before and at 8am
-normal neg feedback leads to cortisol <50mmol/L
-Cushing’s - failure to suppress
What is Addison’s disease?
A primary adrenal insufficiency resulting from destruction of the entire adrenal cortex
What hormone deficiencies are present in Addison’s disease?
Glucocorticoid (cortisol)
Mineralocortiocoid
Sex-steroids
What are the causes/risk factors for Addison’s disease?
Autoimmune (80% UK) TB (most common worldwide) Overwhelming sepsis Metastatic lung/breast cancer Lymphoma Adrenal haemmorhage
What are the symptoms of Addison’s disease?
Weight loss Malaise Weakness Myalgia Syncope Depression
What are the signs of Addison’s disease?
Pigmentation (new scars, palmar creases)
Postural hypotension
Signs of dehydration
Loss of body hair
How is Addison’s diagnosed?
FBC (anaemia)
U&Es (low sodium, high potassium, uraemia)
Raised Ca
Low glucose
Synacthen test (raised cortisol excludes Addison’s)
9am Cortisol (raised ACTH & low/normal cortisol =dx)
CXR/adrenal CT
Describe the Synacthen test
Give ACTH analogue
Measure plasma cortisol before and 30 minutes after
>550nmol/L excludes Addison’s
Describe the 9am ACTH test
Raised ACTH w/ low/normal cortisol = Addison’s
If cortisol high then ACTH level can identify cause of Cushing’s
What is an Addisonian crisis?
Severely inadequate levels of cortisol Presents w/ -fever -nausea/vomiting -shock -hypoglycaemia -hypernatremia & hypokalaemia
What is Conn’s syndrome?
Adrenal adenoma leading to primary hyperaldosteronism
Responsible for 60% of primary hyperaldosteronism
What are the main physiological effects of hyperaldosteronism?
Sodium and water retention
Knock on hypokalaemia
What are the symptoms of Conn’s syndrome?
Mostly asymptomatic
What are the signs of Conn’s syndrome?
Hypertension (treatment resistant, causing headaches) Features of hypokalaemia -cramps -weakness -tetany -polyuria
What are the biochemical signs of Conn’s syndrome?
Hypokalaemia w/ urinary K loss
Elevated plasma aldosterone:renin
How is Conn’s syndrome distinguished from adrenal hyperplasia?
Adrenal CT Adrenal scintography (unilateral uptake of isotope)
What is a Phaechromocytoma?
Catecholamine secreteing tumours arising from sympathetic paraganglial cells (Chromaffin cells)
Where are Phaechromocytomas commonly found?
> 70% Adrenal medulla
10% extra-adrenal
10% are bilateral
10% familial (MEN IIa/IIb, NF, VHL syndrome)
How do Phaechromocytomas present?
Severe/episodic HTN unresponsive to treatment
Vague/episodic symptoms in several systems
