Cushings disease Flashcards
what causes cushings syndrome?
excess cortisol
what general biochemical changes does cushings syndrome cause?
protein loss altered carbohydrate/lipid metabolism - diabetes, obesity altered psyche - depression, psychosis excess mineralocorticoid excess androgen
what does protein loss cause in cushings?
myopathy, wasting osteoporosis, fractures thin skin striae bruising
what does the excess mineralocorticoid in cushings cause?
hypertension
oedema
what does excess androgen in cushings cause?
virilism
hirsutism
acne
oligo/amenorrhoea
what features distinguish cushings from obesity?
thin skin proximal myopathy frontal balding in women conjunctival oedema (chemosis) osteoporosis
what is the most common test for cushings?
exogenous oral high dose steroid (dexamethasone)
- should cause low serum cortisol
describe dexamethasone suppression test?
overnight 1mg dexamethasone
- normal = cortisol <50 nmol the nest mornine
- cushings = >100 nmol/L
what other tests can screen for cushings?
4 hr urine free cortisol
- should be <250
diurinal cortisol variation(midnight/8am)
what is the definitive test for cushings?
low dose dexamethasone suppression test
- 2 day 2mg/day dexamethasone suppression test
- cortisol <50 = normal
- cortisol >130 = definitely cushings
what are the 2 types of cushings?
cushings disease (pituitary) cushings syndrome
what can cause cushings syndrome?
adenoma of adrenal glands (benign/cancer) ectopic (thymus, lung, pancreas) pseudo - alcohol and depression - steroid medication
how do pituitary, adrenal and ectopic cushings differ in test results?
pituitary = abnormal dexa test, ACTH <300, high dose dexa suppression = 50% adrenal = abnormal dexa test, ACTH <1, no high dose dexa suppression ectopic = abnormal dexa test, ACTH >300, no high dose dexa suppression
what does CRH test show in cushings DISEASE?
50% increase in ACTH
20% increase in cortisol
how is pituitary cushings disease managed?
hypophysectomy and external radiotherapy if it recurs
bilateral adrenalectomy
how is adrenal cushings managed?
adrenalectomy
how is ectopic cushings managed?
remove source
or
bilateral adrenalectomy
how can cushings be managed pharmacologically?
metyrapone (if other treatments fail or waiting for radiotherapy to work)
ketoconazole (hepatotoxic)
pasireotide LAR (somatostatin analogue)
what are the features of pan hypopituitarism?
GH = growth failure TSH = hypothyroid LH/FSH = hypogonadism ACTH = hypoadrenal Prolactin = no effects
what are the features of pan hypopituitarism in posterior pituitary?
diabetes insipidus
what can cause hypopituitarism?
primary tumours secondary metastatic tumours local brain tumours granulomatous disease (TB, sarcoidosis etc) vascular disease trauma hypothalamic disease iatrogenic autoimmune (sheenan) infection (meningitis)
what are the symptoms of anterior hypopituitarism in females?
menstrual irregularities infertility, impotence abdo obesity loss of axillary and pubic hair dry skin and hair hypothyroid faces growth retardation (in children)
what are the symptoms of anterior hypopituitarism in males?
infertility, impotence gynaecomastia abdo obesity loss of facial hair loss of axillary and pubic hair dry skin and hair hypothyroid faces growth retardation (in children)
what are the best tests for checking the steroid axis (cortisol etc)?
synacthen
insulin tolerance
