Adrenal Disease Flashcards
what are the two main adrenal medullary tumours?
neuroblastoma
pheochromocytoma
from what cells is pheochromocytoma derived?
chromaffin cells of the adrenal medulla
what does pheochromocytoma secrete?
catecholamines
why is pheochromocytoma called the 10% tumour?
10% are extra adrenal
10% are bilateral
10% are malignant
10% are not associated with hypertension
which adrenal disorder is associated with dark skin?
addison’s disease (high ACTH)
what are the main primary adrenal insufficiencies?
addison’s disease
congenital adrenal hyperplasia
malignancy
adrenal TB
what is the most common cause of primary adrenal insufficiency?
addison’s disease
is addison’s disease an autoimmune disease?
yes
associated with autoantibodies in the majority of cases
list clinical features of addison’s disease
dizziness low BP fatigue anorexia skin pigmentation
what would sodium and potassium levels be like in addison’s disease?
low sodium
high potassium
which diagnostic test is used for Addison’s disease?
short synACTHen test
outline management for adrenal insufficiency
hydrocortisone 30mg
fludrocortisone
true or false: patients on hydrocortisone for adrenal insufficiency can stop whenever they want
false
never stop suddenly, but the dose can be reduced
list causes of secondary adrenal insufficiency
pituitary/hypothalamic tumours
exogenous steroid use
what is the effect of exogenous steroid on the H-P-adrenal cortext axis?
suppress CRH and ACTH
what hormone is in excess in cushing’s syndrome?
cortisole
true or false: cushing’s syndrome is more common in men
false
list clinical features of cushing’s syndrome
moon face abdominal striae thin skin easy bruising proximal myopathy osteoporosis
what are the ACTH dependent causes of cushing’s syndrome?
pituitary disease/adenoma
ectopic tumours
what are ACTH independent causes of cushing’s syndrome?
adrenal disease/adenoma
nodular hyperplasia
what is the gold standard test for diagnosing cushing’s syndrome?
low dose dexamethasone suppression test
what is the most common cause of cortisol excess?
high dose steroid therapy
what is primary aldosteronism?
autonomous production of aldosterone independent of its regulators
which syndrome occurs due to aldosteronism?
conn’s syndrome
what is the most common cause of secondary hypertension?
primary aldosteronism
outline how an aldosterone excess is diagnosed
measure aldosterone:renin ratio
if raised, do saline suppression test
failure of aldosterone to suppress by 50% with 2L saline confirms aldosteronism
what are the main causes of aldosteronism?
adrenal hyperplasia
adrenal adenoma
genetic mutations
outline management of primary aldosteronism
adrenalectomy if unilateral adenoma
spironolactone if bilateral hyperplasia
what is the most common cause of congenital adrenal hyperplasia?
21-alpha-hydroxylase deficiency
what three main effects does 21-alpha-hydroxylase deficiency cause?
low cortisol
low aldosterone
excess androgens
what is the classical triad of symptoms in pheochromocytoma?
hypertension
headache
sweating
how is pheochromocytoma diagnosed?
MRI
MIBG
PET scan
outline therapy for pheochromocytoma
alpha blockers
beta blockers
fluid replacement
surgical excision
pheochromocytoma is associated with which clinical syndromes?
MEN 2 von hippel lindau succinate dehydrogenase mutations neurofibromatosis tuberous sclerosis
which gene is affected in MEN 1?
MEN1 gene (11q)
which gene is affected in MEN 2?
RET gene (10q)
true or false: the MEN1 gene is a tumour suppressor
true
is the RET gene a tumour suppressor or a proto-oncogene?
proto-oncogene
von hippel lindau syndrome is caused by a mutation in which gene?
VHL gene
list the parts of the adrenal gland
outer capsule
cortex
medulla
what are the three zones located in the adrenal cortex?
zona glomerulosa
zona fasciculata
zona reticularis
which cells are located in the adrenal medulla?
chromaffin cells
what controls hormonal release in the zona glomerulosa?
RAAS (angiotensin II)
which hormone is secrete from the zonua glomerulosa?
aldosterone
what controls hormonal release in the zona fasciculata?
ACTH
what hormones are secreted from the zona fasiculata?
cortisol
corticosterone
what controls hormonal release in the zona reticularis?
ACTH
what hormones are secreted from the zona reticularis?
androgens
what controls hormonal release in the adrenal medulla?
sympathetic nervous system
what hormones are secreted from the adrenal medulla?
catecholamines
outline the hypothalamus pituitary adrenal cortex axis
HYPOTHALAMUS secretes CRH which stimulates anterior PITUITARY to secrete ACTH which stimulates the ADRENAL GLAND to secrete cortisol
which part of the H-P-adrenal cortex axis does cortisol inhibit in negative feedback?
hypothalamus
anterior pituitary
which system regulates aldosterone release?
RAAS
what is the effect of cortisol upon the CNS?
varying mood
psychosis
loss of libido
what is the effect of cortisol upon bone?
osteoporosis
what is the effect of cortisol upon metabolism?
increases breakdown of carbs, lipids and proteins
what are the main effects of aldosterone?
increased K + H ion excretion
sodium retention
