adrenal pathology Flashcards
what are some examples of primary adrenal insufficiency
- addison’s disease
- congenital adrenal hyperplasia
- adrenal TB/malignancy
what are some examples of secondary adrenal insufficiency
- due to lack of ACTH stimulation
- iatrogenic (excess exogenous steroid)
- pituitary/hypothalamic disorders
causes of primary adrenal insufficiency
- autoimmune/addison’s disease
- APS type 1
- APS type 2
- infections
- bilateral adrenal haemorrhage
- bilateral adrenal metastases
- bilateral adrenal infiltration
- bilateral adrenalectomy
- drug induced
- genetic disorders
causes of secondary adrenal insufficiency
- pituitary tumours
- pituitary surgery
- pituitary irradiation
- trauma
- infections
- pituitary apoplexy
- sheehan’s syndrome
- genetic disorders
causes of tertiary adrenal insufficiency
- hypothalamic tumours
- hypothalamic surgery
- hypothalamic irradiation
- infections
- trauma
- Cushing’s syndrome
- drug induced
clinical features of Addison’s disease
- anorexia, weight loss
- fatigue/lethargy
- dizziness and low BP
- abdo pain
- vomiting
- diarrhoea
- skin pigmentation
what is addisons
autoimmune destruction of the adrenal cortex
commonest cause of primary adrenal insufficiency
diagnosis of adrenal insufficiency
biochemistry
- decrease Na increase K and hypoglycaemia
- short synACTHen test
- ACTH levels should be increased
- renin should be increased and aldosterone should be decreased
- adrenal antibodies
management of adrenal insufficiency
- hydrocortisone as cortisol replacement (15-30mg daily)
- fludrocortisone as aldosterone replacement
- need education
emergency treatment of adrenal crisis
- IV hydrocortisone
- IV fluid resuscitation
- cardiac monitoring
- careful monitoring of electrolyte fluid balance
sick day rule 1
moderate intercurrent illness, surgical procedure under local anaesthetic
double usual daily glucocorticoid use
sick day rule 2
severe intercurrent illness, preparation for colonoscopy, acute trauma or surgery
cause of secondary adrenal insufficiency
- pituitary/hypothalamic disease tumours
- exogenous steroid use
- genetic
- pituitary surgery
- trauma
- infection
- sheehan’s syndrome
examples of exogenous steroid use
- high dose prednisolone
- dexamethasone
- inhaled corticosteroid
causes of tertiary adrenal insufficiency
- hypothalamic tumours
- hypothalamic surgery
- hypothalamic irradiation
- infections
- trauma
- cushing’s
- drug induced
what is secondary adrenal insufficiency
inadequate ACTH stimulating the adrenal glands, resulting in low levels of cortisol being released. This is the result of loss or damage to the pituitary gland.
what is tertiary adrenal insufficiency
inadequate CRH release by the hypothalamus. This is usually the result of patients being on long term oral steroids (for more than 3 weeks) causing suppression of the hypothalamus.
difference between addison’s and secondary adrenal insufficiency clinical features
secondary:
- skin pale
- aldosterone production is intact
what does long term steroid treatment do to ACTH production
suppresses it
implications of atrophy of adrenal cortex
- unable to respond to stress (illness/surgery)
- need extra doses of steroid when ill/surgical procedure
- cannot stop suddenly
- gradual withdrawal of steroid therapy if >4-6 weeks
what is primary aldosteronism
autonomous production of aldosterone independent of its regulators
what are the cardiovascular actions of aldosterone
- increase cardiac collagen
- cytokines and ROS synthesis
- sodium retention
- altered epithelial function (increased pressor response)
- increase sympathetic outflow
what is the commonest secondary cause of hypertension
primary aldosteronism
clinical features of aldosteronism
- significant hypertension
- hypokalaemia
- alkalosis
what are the subtypes of primary aldosteronism
- adrenal adenoma (Conn’s syndrome)
- bilateral adrenal hyperplasia
- rare causes (genetic, unilateral hyperplasia)
diagnosis of primary aldosteronism
- confirm aldosterone excess by measuring aldosterone/renin ratio and if raised do saline suppression test (failure of aldosterone to suppress by >50% with 2 litres of normal saline confirms PA)
- confirm subtype - adrenal CT to confirm adenoma
management of primary aldosteronism
surgical
-unilateral laparoscopic adrenalectomy if adenoma
medical
-MR antagonists (spironolactone or eplerenone)
what is congenital adrenal hyperplasia
Congenital adrenal hyperplasia is caused by a congenital deficiency of the 21-hydroxylase enzyme. This causes underproduction of cortisol and aldosterone and overproduction of androgens
when is classic CAH typically diagnosed
infancy
what is non-classic CAH
- partial 21alpha-hydroxylase deficiency
- presents in adolescence
presentation of classical CAH
- adrenal insufficiency
- poor weight gain
- tall for their age
- genital ambiguity
- facial hair
- deep voice
- absent periods
- early puberty
presentation of non-classical CAH
- hirsute
- acne
- oligomenorrhoea
- precocious puberty
- infertility or sub-fertility
treatment for CAH in children
- glucocorticoid replacement with hydrocortisone
- aldosterone replacement with fludrocortisone
- surgical correction
treatment for CAH in adults
- control androgen excess
- restore fertility
- avoid steroid over-replacement
what are some clues to phaechromocytoma
- labile hypertension
- postural hypertension
- paroxysmal sweating, headache, pallor, tachycardia
what are extra adrenal tumours called
paraganlioma
symptoms of paraganglioma/phaechomocytoma
HYPERTENSION HEADACHE SWEATING -palpitations -breathlessness -constipation -anxiety -weight loss -flushing
signs of paraganglioma/phaechromocytoma
- hypertension
- postural hypotension
- pallor
- bradycardia
- tachycardia
- pyrexia
signs of complications of paraganglioma/paechromocytoma
- left ventricular failure
- myocardial necrosis
- stroke
- shock
- paralytic ileus of bowel
biochemical abnormalities seen in paraganglioma/phaechromocytoma
- hyperglycaemia
- low potassium
- high Hb concentration
- mild hypercalcaemia
- lactic acidosis
who should we investigate for paraganglioma/phaechromocytoma
- family members with syndromes
- resistant hypertension
- under 50s with hypertension
- classical symptoms
- consider with hypertension and hyperglycaemia
what are the main catecholamines
adrenaline, noradrenaline and dopamine
diagnosis of phaechromocytoma/paraganglioma
confirm catecholamine excess -urine and plasma MRI scan (abdomen, whole body) MIBG PET scan
preparation for surgery of paraganglioma/phaechromocytoma
full alpha and beta blockade
- phenoxybenzamine for alpha
- propanolol, atenolol or metoprolol for beta
fluid and/or blood replacement
careful anaesthetic assessment
treatment for phaechromocytoma/paraganglioma
surgical
- laparoscopic
- total excision
- chemotherapy if malignant
- radiolabelled MIBG
clinical syndrome associated with phaechromocytoma and paraganglioma
- MEN2
- Von-Hippel-Lindau syndrome
- succinate dehydrogenase mutations
- neurofibromatosis
- tuberose sclerosis
