Adrenal Nodules

What are the Adrenal Glands and what do they do?

The adrenal glands are small, pyramidal shaped organs which sit on top of the kidneys. They produce hormones that are very important for the healthy function of your body. The adrenal medulla makes adrenaline and other related hormones which you need for the ‘fight or flight’ response. The cortex makes several hormones including aldosterone which is an important hormone for controlling blood pressure and your body’s salt levels. It also makes the hormone cortisol which is an important ‘stress hormone’. Small amounts of sex hormones are also made by the adrenal but these are not usually of any significance in the context of adrenal nodules.

What problems can adrenal nodules cause?

Most adrenal nodules cause no symptoms at all. In fact, many of them are discovered incidentally on scans targeting other parts of your body and for this reason are often called ‘adrenal incidentalomas’. The majority of adrenal nodules don’t need any treatment but when treatment is recommended it is usually for one of two reasons:

• Overproduction of hormones (we call these nodules ‘functional’). When the cause of the excessive hormone production is the adrenal nodule these conditions are given certain medical names:
  - Too much adrenaline = Phaeochromocytoma (Fee-oh-chrome-oh-cytoma)
  - Too much aldosterone = Conn’s syndrome
  - Too much cortisol = Cushing’s syndrome
• Size. The bigger an adrenal nodule is the greater the risk is that the lump might be cancerous. Adrenal cancer is very rare and only occurs in about 1 in 1,000,000 New Zealanders per year.

I will fully assess your adrenal nodule to decide if it is functioning or if there is a risk of cancer.

How will my adrenal nodule be assessed?

This assessment starts with asking you some questions, examining you and checking your blood pressure. In addition to this you will need to have blood tests, and sometimes urine tests, to look at the levels of the adrenal hormones in your body. Some types of medication can interfere with these tests so it is important that you bring a list of these to your appointment. These tests are may be co-ordinated by an Endocrinologist (medical specialists who treat conditions caused by hormone dysfunction). It is important that you follow the instructions for these tests precisely to ensure that the results are accurate.

There are many tests for each of the adrenal hormones but typically you will have the following tests:

• ‘U&E’ – a blood test to check on the salt levels in your body
• Aldosterone:Renin ratio (blood test)
• Overnight dexamethasone suppression test – a blood test where you take a tablet at night and have a blood test at a specific time the following morning to look at the levels of cortisol in your body. (You will be given a prescription for the tablet)
• Urinary or blood ‘catecholamines and metanephrines’ – these test your levels of adrenaline and other related hormones. The choice of which test you have will be based on some of the answers to the questions I ask.