Endo- adrenal disorders Flashcards
what is cushings syndrome
increased free circulating glucocorticoid
what differentiates cushings syndrome from cushings disease
cushings disease is when the increased cortisol levels are caused by a functioning pituitary adenoma; all other causes are referred to as cushings syndrome
ACTH dependent causes of cushings syndrome/disease
pituitary adenoma (68%)
ectopic ACTH- carcinoid/carcinomas
ectopic CRH
ACTH independent causes of cushings syndrome
exogenous steroids
adrenal adenoma or carcinoma
Adrenal cortical nodular hyperplasia
what are some conditions which cause a false positive for cushings syndrome (pseudo)
severe depression
severe alcoholism
general clinical features of cushings syndrome
plethora (red face)
moon face
hypertension
central obesity
depression/psychosis
Glycosuria/diabetes mellitus
oedema
‘buffalo hump’
Virilism
clinical features of the skin in cushings syndrome
brushing
striae
pigmentation (only ACTH dependant cause)
thin skin
hirsutism
acne
MSK clinical features in cushings syndrome
proximal myopathy, wasting
osteoporosis, fractures
first line investigation for cushings syndrome
overnight 1mg dexamethasone suppression test (oral)
normal- cortisol <50 nmol/l next morning
abnormal- cortisol >130 nmol/l
what is primary adrenal insufficiency (addisons disease)
decreased production of adrenocortical hormones (glucocorticoids, mineralocorticoids, and adrenal androgens)
most common cause of Addisons disease
autoimmune adrenalitis- 80-90% of all cases
what other autoimmune diseases are associated with Addisons disease
T1DM
thyroid autoimmune diseases
penicious anaemia
other causes of Addisons disease other than autoimmune adrenalitis
infectious- tb, CMV disease, HIV
metastatic malignancy- lung, breast
adrenal haemorrhage
what electrolyte imbalances occur in Addisons disease due to decreased mineralocorticoids
potassium retention
sodium loss
what are the clinical consequences in Addisons disease of decreased mineralocorticoids
hyperkalaemia
hyponatraemia
volume depletion
hypertension
what metabolic effect is caused in Addisons disease by decreased glucocorticoids
hypoglycaemia
clinical features of Addisons disease
S+S occur once >90% gland destroyed
vague symptoms- weak, anorexic, fatigue, N+V, weight loss, diarrhoea, dizziness and low bp, abdominal pain
skin pigmentation- look ‘tanned’, black spots in buccal mucosa, dark palmar creases and finger spaces
what percentage of patients with Addisons disease will have positive adrenal autoantibodies
about 70%
what biochemical abnormalities are typically seen in Addisons disease
decreased sodium
increased potassium
possibly hypoglycaemia (especially in paeds)
renin/aldosterone levels in Addisons disease
> renin
< aldosterone
what is the purpose of the Short synacthen test
to assess adrenal gland response to ACTH stimulation
what is the primary medication used for cortisol replacement in Addisons disease
hydrocortisone
what medication is used to replace aldosterone in Addisons disease
fludrocortisone
gold standard investigation for Addisons disease
short synacthen test
in which part of the adrenal gland are mineralocorticoids produced (eg aldosterone)
zona glomerulosa
in which part of the adrenal gland are glucocorticoids produced (eg cortisol)
zona fasciculata
what is an adrenal adenoma
benign neoplasm emerging from the cells of the adrenal cortex
what colour are the majority of adrenal adenomas
bright yellow
what are adrenocorticiol carcinomas
very rare malignancy of the adrenal cortex
which are rarer adrenal adenomas or adrenocorticol carcinomas?
adrenocorticol carcinomas
what can adrenocorticol carcinomas be associated with in younger patients
Li-Fraumeni syndrome
clinical features of adrenocorticol carcinomas
hormonal effects
abdominal mass effects
carcinomas with necrosis can cause fever
what is primary hyperaldosteronism
autonomous production of aldosterone independent of its regulators (angiotensin II/potassium)
what is Conns syndrome
primary hyperaldosteronism caused by adrenal adenoma
what is the commonest secondary cause of hypertension
primary hyperaldosteronism
clinical features of primary hyperaldosteronism
significant hypertension
hypokalaemia (~30%)
alkalosis
initial screening test for conns syndrome
aldosterone to renin ratio
90% of congenital adrenal hyperplasia due to what genetic inheritance
autosomal recessive 21a-hydroxylase deficiency
what does 21a-hydroxylase deficiency prevent the production of
aldosterone and cortisol
