Adrenal disorders Flashcards
Features of Cushing’s syndrome (4)
- Excess cortisol
- Loss of hypothalamic pituitary axis feedback
- Loss of circadian rhythm
- Most commonly caused by steroids or ACTH
Define Cushing’s disease
Cushing’s syndrome specifically caused by pituitary adenoma. Bilateral adrenal hyperplasia.
30-50y
Define Cushing’s syndrome
Abnormalities caused by excess circulating glucocorticoids (from any cause)
Causes of Cushing’s syndrome (6)
- Cushing’s disease
- Ectopic ACTH production - small cell lung cancer, carcinoid tumours
- Ectopic CRF production - some thyroid medullary and prostate cancers
- Iatrogenic
- Adrenal adenoma/cancer
- Adrenal nodular hyperplasia
Symptoms of ectopic ACTH production (4)
- Hyperpigmentation (increased ACTH)
- Hypokalaemia metabolic alkalosis
- Hyperglycaemia
- Weight loss
Pathology of Cushing’s syndrome (3)
- Excess ACTH -> excess cortisol production
- Pathology in adrenals -> zona reticularis stimulated to produce more cortisol
- Synthetic glucocorticoids
Symptoms of Cushing’s syndrome: CUSHING
Cataracts Ulcers Striae - purple stripes on abdomen Hypertension and hyperglycaemia Increased risk of infection Necrosis Glucosuria (also amenorrhea - absence of period)
Signs of Cushing’s disease (7)
- Truncal/central obesity
- Moon face
- Buffalo hump - fatty lump on upper back
- Acne
- Hirsutism - male hair pattern in females
- Thin skin/bruising
- Osteoporosis
Investigations of Cushing’s syndrome (5)
- Random cortisol test - if high proceed to next
- Overnight dexamethasone suppression test
- Check 24h urinary free cortisol measurement - if normal Cushing’s unlikely
- CT/MRI
- Plasma ACTH
Differential diagnosis of Cushing’s syndrome
Pseudo-cushing’s - caused by excess alcohol consumption and resolves after 1-3wks abstinence
Treatment of Cushing’s syndrome (5)
- Iatrogenic - stop drugs
- Cushing’s disease - transphenoidal removal of pituitary adenoma
- Adrenal adenoma - adrenalectomy
- Adrenal carcinoma - adrenalectomy, RT, adrenolytic drugs
- Ectopic ACTH - surgery to remove tumour
Define acromegaly
Excessive production of growth hormone in adults after epiphyseal fusion
Causes of acromegaly (2)
- Benign GH-producing pituitary adenoma - develops over years
- Ectopic GH-producing hormone from carcinoid tumour
RF acromegaly
Associated with multiple endocrine neoplasia - MEN-1
Pathology of acromegaly
Increased GH production -> increased IGF-1 -> stimulates skeletal and soft tissue growth - giant like appearance.
Local tumour expansion in pituitary gland will apply pressure to surrounding structures causing headaches and vision field loss
Symptoms of acromegaly (6)
- Acroparaesthesia
- Arthralgia
- Amenorrhoea/oligomenorrhoea
- Sweating
- Decreased libido/impotence
- Galactorrhoea
Signs of acromegaly (10)
- Acral enlargement - hands, feet, jaw
- Big tongue and widely spaced teeth
- Prominent supraorbital ridge
- Puffy eyelids, lips, skin
- Darkening skin
- Obstructive sleep apnoea
- Thick skin
- Deep voice
- HTN
- HF
Investigations for acromegaly (6)
- Oral glucose tolerance test - usually glucose will reduce GH in blood
- Serum IGF-1 levels - raised
- Pituitary fossa MRI
- Visual field tests
- ECG and echocardiogram
- Serum prolactin - can be raised from adenoma
Treatment of acromegaly
- First line - transphenoidal surgical resection of pituitary adenoma
- Second line - somatostatin analogues (suppress GH secretion), dopamine agonist, GH antagonist, external radiotherapy
Define Conn’s syndrome
Hyperaldosteronism due to primary aldosterone producing adenoma
RF Conn’s
HTN
Pathology of Conn’s
- Excess production of aldosterone independent of the RAAS system
- Increased K+ loss, Na+ and water retention -> BP increase
- Decreased renin release
- Hypokalaemia
Symptoms of Conn’s
1. Usually asymptomatic Hypokalaemia symptoms: 2. Constipation 3. Muscle weakness and cramps 4. Polyuria and polydipsia 5. Paraesthesia 6. Sweating attacks - unusual
Signs of Conn’s
- HTN as result of increased blood vol
2. Cardiac arrhythmias - especially in patients with cardiac disease
Differential diagnosis of Conn’s
Secondary hyperaldosteronism - excess renin
Causes: renal artery stenosis, accelerated HTN, diuretics, hepatic failure, congestive heart failure
Investigations for Conn’s
- U&Es - decreased renin, increased aldosterone
- ECG - U waves, flat T waves, Long PR, Long QT, ST depression
- Adrenal CT/MRI
Treatment for Conn’s
- Laparoscopic adrenalectomy
2. Spironolactone - K+ sparing diuretic - aldosterone antagonist
