Adrenal insufficiency/lesions

Question 1

Adrenal insufficiency/lesions:

What is it, who is affected and why?

Answer 1

Cortisol deficiency primarily, but may also include aldosterone insufficiency

Paediatrics - M > F 3:1
-primarily congenital

Adults - F > M 3:1

• 80% autoimmune
• Other causes include TB, histoplasmosis, cryptococcous, CMV

Question 2

Adrenal insufficiency/lesions:

Types of Adrenal Insufficiency?

Answer 2

Primary

1) Neonatal/early childhood
- 95% of cases due to 21 hydroxylase insufficiency (cant metabolise hormones into cortisol)
- no adrenal destruction so ACTH will be increased to drive production and adrenals will be hyperplastic but non functional
- normally will present with hypoglycaemia/seizures during times of illness (often missed)

2) Addison Disease
- Adrenal cortex destruction via autoimmune process
- Anti Adrenal Antibodies positive
- other associated autoimmune diseases in 50% (Thyroid, hypoparathyroidism, DMT1)
- Bloods - morning cortisol, ACTH, 24hr urine cortisol, aldosterone levels, anti adrenal Ab

Secondary (Aldosterone will be normal)

1) Hypothalamus Pituitary Axis suppression
- iatrogenic exogenous steroids

2) Pituitary disease
- loss of ACTH production

Question 3

Adrenal insufficiency/lesions:

Addisons symptoms?

Answer 3

Weakness 99%
fatigue
weight loss 97%
anorexia
abdominal pain 34%
diarrhoea/constipation 20%
confusion/psychosis/mood disturbance
postural hypotension
hyperpigmentation (non sun exposed areas - eg axilla. groin, gums)

Question 4

Adrenal insufficiency/lesions:

What is an adrenal crisis and how is it managed?

Answer 4

Precipitated by:

• steroid withdrawal
• stress
• infection
• trauma
• dehydration

Adrenal crisis:

• reduced GCS
• haemodynamic instability
• hypoglycaemia
• hyponatraemia
• hyperkalaemia
• seizures

Management

• IV hydrocortisone
• correct electrolyte derrangement
• correct hypoglycaemia
• control seizure activity

Question 5

Adrenal insufficiency/lesions:

Addisons management?

Answer 5

• Hydrocortisone (cortisol substitute)
• If lacking aldosterone then will also need Fludrocortisone

1) Education on condition and importance of medication compliance
2) link with endocrinologist
3) Ensure action plan
- triple dose of hydrocortisone for 3 days during stress
4) osteoporosis prevention due to longterm corticosteroids
5) monitor for development of other autoimmune conditions

Question 6

Adrenal insufficiency/lesions:

Incidental adrenal lesions?

Answer 6

20% have subclinical hormonal abnormalities
If no previous cancer then 3% will be metastatic
If previous cancer then 50 - 75% will be metastatic

Approach after identifying incidental adrenal lesion

1)
a) Dexamethasone suppression test
- 1mg at 2300hrs to determine cortisol source
- 91% sensitive
- if abnormal needs endocrinology confirmation

b) 24hr urinary metanephrines/catecholamines
- best for screening 90% sensitive 98% specific (serum metanephrines is too sensitive for screening)
- 15% of phaeochromocytomas are asymptomatic or normotensive

c) Renin/aldosterone ratio

2) Assess the imaging characteristics
If lesion is ≥4cm OR <4cm AND radiologically suspicious then get specialist opinion

Suspicious adrenal lesions are determined by contrast washout:

• benign lesions have a 50% washout of contrast at 10 minutes
• 100% sensitive and 98% specific

Most lesions then get yearly imaging for 2 years to ensure they remain stable.