Adrenal Pathology Flashcards
list the causes of primary adrenal insufficiency
auto-immune
infection eg TB
adrenal metastasis eg from breast, bone or kidney
what is Addisons disease
autoimune destruction of the adrenal glands - most common cause of primary adrenal insufficiency
in primary adrenal insufficiency describe levels of cortisol, aldosterone and ACTH
cortisol and aldosterone low
ACTH high due to negative feedback still taking place
describe the clinical presentation of addisons disease
myalgia and arthraglia abdo pain, diarrhoea and vomiting dizziness weight loss and fatigue hyperpigmentation of the skin
what is the pathophysiology behind hyperpigmentation of addisons disease
increased levels of ACTH cause deposits in the skin
describe sodium, potassium and glucose levels in a patient with Addisons disease
sodium low
potassium high
glucose low
how is primary adrenal insufficiency diagnosed
short synthacten test - administer synthetic ACTH which should increase levels of cortisol gradually eg after 30 mins levels greater than 550
Addisons disease will show no significant increase in cortisol levels
how is Addisons disease managed
steroid replacement therapy
hydrocortisone 15-25mg and fludrocortisone
is dosing of steroid replacement therapy divided up and why
yes divided up and cortisol typically peaks in morning and low at night, dosages must follow this regime
what occurs if Addisons disease goes untreated
Addisonians crisis - presents with shock, hypogylcaemia and confusion usually following surgery or not taking steroids
describe the management of Addisonians crisis
fluid resuscitation, IV hydrocortisone and IV glucose if necessary
what is bilateral adrenal hyperplasia
congenital form of adrenal insufficiency due to mutation
what mutation causes bilateral adrenal hyperplasia
21 alpha hydroxylase enzyme - causes reduced cortisol and aldosterone whilst increases androgens
bilateral adrenal hyperplasia presents differently in adults and children, how does it present in children
dehydration salt crisis failure to thrive girls - ambiguous genitalia boys - early virilisation
how does bilateral adrenal hyperplasia present in adult men and women
men - acne, short stature, precocious puberty
women - hirsutism, oligomenorrhoea, reduced stature, acne
describe the management of bilateral adrenal hyperplasia
same as addisons with steroid replacement therapy
girls - requires karyotyping and gender assignment
what is secondary adrenal insufficiency
deficiency of ACTH which then leads to reduced cortisol levels
list some causes of secondary adrenal insufficiency
pituitary disease eg tumour or trauma
long term steroid use - dampens the steroid axis over time
in secondary adrenal insufficiency both cortisol and aldosterone are reduced true/false
false only cortisol is reduced
this means presentation is similar to addisons except no dehydration or hyperpigmentation
how is secondary adrenal insufficiency treated
oral hydrocortisone
what is primary hyperaldosteronism
excessive production of aldosterone independent of RAAS
what is the main causes of primary hyperaldosteronism
Conns syndrome - aldosterone secreting adrenal adenoma
describe the presentation of Conn’s Syndrome
polydipsia polyuria headaches weakness/muscle cramps/spasms hypertension - especially young patients and resistant
describe sodium and potassium levels in Conn’s syndrome
Na high
K low
CT of abdomen will identify adenoma
outline the management of Conns syndrome
conservative - aldosterone antagonist eg spironolactone
surgical - removal of adenoma
what is Cushings syndrome
any condition causing excess cortisol production
list exogenous and endogenous causes of Cushings syndrome
exogenous - prolonged steroid use
endogenous - ACTH independent and ACTH dependent
list ACTH independent causes of Cushings syndrome
benign adrenal adenoma
adrenal carcinoma
list ACTH dependent causes of Cushings syndrome
ectopic ACTH production eg lung tumour
pituitary adenoma secreting ACTH
describe the presentation of Cushings syndrome
central abdominal obesity with striae proximal muscle wasting moon face virilisation and hirsuitism oligomenorrhoea hypertension, osteoporosis, easy bruising, thin skin
what is the screening test for Cushings syndrome
overnight dexamethasone suppression test
what is the diagnostic test for Cushings syndrome
48 hour dexamethasone suppression test - if cortisol is less than 50 patient does not have Cushings
how is the cause of Cushings syndrome investigated
CT/MRI of abdomen or plasma ACTH
outline the management of Cushings
surgical excision of adenoma if present
adrenal enzyme inhibitors - metyrapone or ketoconazole
phaeochromocytoma is a tumour of __ and secretes __
tumour of adrenal medulla
secretes excess catecholamines
list the triad of symptoms that present in phaeochromocytoma
hypertension
headaches
sweating
also sob, facial flushing and chest tightness
how is a suspected phaeochromocytoma investigated
24 hour urine collection of catecholamines
MIBG scan - uses a chromaffin seeking isotope to look for increases uptake
how is a phaeochromocytoma managed
surgical excision
before surgery requires blood pressure protection through alpha blocker - phenoxybenzamine and beta blocker - atenolol
