Adrenal Disease Flashcards
What is Cushing’s syndrome?
A syndrome characterised by excess cortisol levels
What are possible reasons for Cushing’s syndrome?
Iatrogenic
- drugs (glucocorditoids mimicking cortisol)
Primary Cushing’s
- cortisol producing adrenal tumour
Secondary Cushing’s (Cushing’s disease)
- Excess ACTH resulting in 2ry hyercortisolism
[] pituitary tumour
[] ACTH secreting ectopic tumour
What are the symptoms associated with Cushing’s syndrome?
Cushingoid appearance
- Moon face, ‘Buffalo hump’, purple striae
Matabolic syndrome
- Central obesity with thin peripheries
- impaired glucose tolerance (pre hyperglycaemia)
- hyperlipidaemia
- hirsutism (abnormal growth of hair on lady’s face/body)
MSK
- Osteoporosis
- proximal myopathy
- avascular necrosis of femoral head
Immunosuppression
Psychiatric: insomnia, mania, depression
GI symptoms: increased risk of PUD, pancreatitis
Water retention => hypertension
Which tests should be used to investigate Cushing’s?
To confirm: 24 hour urinary cortisol will be high
To differentiate:
- ACTH levels
- Dexamethasone (mimicks cortisol) suppression test
[] low dose will suppress cortisol in normal
[] high dose will suppress cortisol in pituitary tumours
[] Won’t suppress cortisol in adrenal/ectopic tumours - CT scan of adrenals
- MRI of pituitary
- Inferior petrosal venous sampling
What is Conn’s syndrome?
Primary hyperaldosteronism
- i.e. not due to renin
- may be a result of:
[] adrenal hyperplasia
[] adrenal adenoma (2/3)
[] adrenal carcinoma (very rare)
What are the clinical findings of Conn’s syndrome?
Usually asymptomatic other than hypertension
- hypertension is often resistant to treatment
- hypokalaemia and hypernatraemia
- retinopathy
Which investigations should be done for suspected Conn’s?
Bloods: ↓ [renin] plasma and ↓K+
CT adrenals - look for adenoma, hyperplasia, tumour
Adrenal venous sampling
How should Conn’s syndrome be treated?
If possible unilateral adrenalectomy in unilateral adenoma
Aldosterone blockers (spironolactone)
What is Addison’s?
Insufficicency of the adrenal gland
What are the causes of Addison’s?
Acute
- sudden withdrawal of long term steroids
- adrenal haemorrhage
Chronic
- Autoimmune adrenalitis, i.e. Addison’s disease (most common cause, although still rare)
- Other primary incl. infection, adrenal mets, drugs
- Hypothalamic causes (v. rare) - tumour, trauma, radio-tx
How do people with Addison’s present?
Often asymptomatic
Postural hypotension
Malaise, N&V
Addisonian crisis
- hypotension
- hypoglycaemia
- collapse
- sudden onset of leg/back/abdo pain
Pigmentation - only in primary causes
Associated Autoimmune disease e.g. DM, vitiligo, hypothyroidism
What investigations are done for diagnosing adrenal deficiency?
Hyponatraemia and Hyperkalaemia due to mineralocorticoid deficiency
Hypoglycaemia due to cortisol deficiency
Decreased 9am cortisol but otherwise normal excludes hypoadrenalism
- in healthy, cortisol levels peak at 9am
What investigations are done for differentiating between primary and secondary adrenal deficiency?
Short SynATCHen test
- IV ACTH given and measure cortisol levels 30mins and 60 mins and compare to baseline
- expect cortisol levels to increase if no primary problem
CT scan - to look for mets in adrenals
21-hydroxylase adrenal antibodies are +ve in >80% of autoimmune aetiologies
How is adrenal deficiency treated?
Replacement of glucocorticoids and mineralocorticoids
- Hydrocortisone (glucocorticoid potent)
- Fludocortisone (mineralocorticoid potent)
What is phaeochromocytoma (and paraganglioma)?
Tumour of the adrenal medulla (tumour of the sympathetic ganglion)
- 10% malignant, 10% familial
Result in excess catecholamine production
What are the symptoms of phaeochromocytoma (and paraganglioma)?
Sweating Tachycardia and hypertension Weight loss Increased blood glucose High urinary catecholamines
What investigations are done for phaeochromocytoma (and paraganglioma)?
24 hour urine collection - look for increased catecholamines and their metabolites
Imaging
How is phaeochromocytoma (and paraganglioma) treated?
alpha-blockers and beta-blockers until surgery can be done
Surgery removed the phaeochromocytoma
What is congenital adrenal hyperplasia?
Autosommal recessive condition characterised by an enzyme deficiency in the cortisol synthetic pathway.
- most commonly 21-hydroxylase deficiency
Low cortisol leads to increased ACTH secretion to maintain adequate cortisol which leads to hyperplasia
Diversion of steroid precursors into the androgenic steroid pathways occurs, thus 17-hydroxyprogesterone, androstenedione, and testosterone levels are increased resulting to virilisation
What are the features of congenital adrenal hyperplasia?
Simple virilising form, sexual ambiguity, short stature
Salt wasting, hypotension, hyponatraemia
Impaired fertility
How is congenital adrenal hyperplasia treated?
Corrective surgery
Mineralocorticoid and glucocorticoid replacement
i.e. fludrocortisone and hydrocortisone
Dexamethasone at night in adult, for treatment of hirsuitism
What investigations are done for diagnosing congenital adrenal hyperplasia?
Measurement of adrenocortical hormones before and one hour after administration of ACTH
- increased DHEAS and androstenedione levels
- increased 17-hydroxyprogesterone levels
[] exagerated response to IV synacthen
