Cushing's Disease Flashcards
cushing’s syndrome
prolonged elevation of glucocorticoid
causes
cushing’s disease - pituitary adenoma
ectopic ACTH tumour - small cell lung cancer
exposure to steroid
adrenal adenoma
signs
moon face round tummy small limbs abdominal striae depression diabetes
investigations
overnight dexamethasone suppression test
OR
24 hr urinary free cortisol test
if abnormal, perform other tests to confirm
once confirmed:
serum midnight ACTH measurement
ACTH raised/normal - ACTH dependent
ACTH low - ACTH independent
MRI - pituitary
CT - ectopic and adrenal adenoma
management
surgically remove tumours
medical therapy to reduce cortisol
which causes are ACTH dependent
pituitary adenoma
ectopic tumour
what is a complication of adrenalectomy
nelson’s syndrome
what medication is used
somatostatin analogues
what test is used to differentiate between pseudo and true cushings
insulin stress test
what is Nelson’s syndrome
the enlargement of a pituitary tumour due to the adrenal glands not secreting cortisol
what electrolyte abnormality is seen
hypokalaemia metabolic alkalosis
what are the results for the dexamethasone tests
pituitary adenoma:
suppressed cortisol and ACTH
adrenal adenoma:
only ACTH is suppressed
ectopic ACTH:
neither are suppressed
