Adrenal tumor – adrenal gland tumor – is non-cancerous in most cases. But it can produce excess hormones and give rise to serious – sometimes life-threatening – conditions such as Cushing’s syndrome, resistant hypertension, palpitations, anxiety, low potassium and abnormal heart rhythm, to name a few.
Now-a-days, an adrenal gland tumor is often discovered incidentally on a CT scan or MRI of abdomen and require further evaluation.
Diagnosis of an adrenal tumor
In the diagnostic evaluation of a tumor on adrenal gland, one has to answer the following two questions:
1- Is the Adrenal tumor producing a hormone?
2- Is the Adrenal tumor benign (non-cancerous) or malignant (cancerous)?
Hormones produced by an adrenal gland tumor
A tumor on adrenal gland may produce one of the following hormones.
3- Catecholamines – adrenaline, nor-adrenaline
An adrenal tumor producing excess cortisol can cause Cushing’s Syndrome.
If adrenal gland produces too much aldosterone, it can lead to aldosteronism.
Excess production of catecholamines can give rise to clinical signs and symptoms of Pheochromocytoma.
Diagnostic tests to detect excess hormone production
1- Tests to detect excess production of cortisol
According to “Endocrine Society Clinical Practice Guidelines“, one of the following tests should be performed as an initial test to assess over-production of cortisol by an adrenal gland tumor..
Overnight 1 mg Dexamethasone Suppression Test.
You ingest 1 mg of Dexamethasone tablet at night. Then, go to a laboratory next morning for a blood draw for cortisol and dexamethasone levels.
24-hour urine for free cortisol.
Your laboratory gives you bottles and instructions how to collect your urine for a 24-hours period.
Midnight salivary cortisol.
You get a kit- and instructions – from your laboratory to obtain a midnight (or late evening) saliva sample for cortisol level.
If you have an abnormal test, your best option is to see an endocrinologist for further diagnostic testing.
2- Which tests can detect excess production of aldosterone ?
The following three tests should be done to see if an adrenal gland tumor is producing too much aldosterone:
- Serum potassium level.
- 24-hour urine for potassium and aldosterone level
- Plasma Renin Activity (PRA) and plasma aldosterone level.
See an endocrinologist if any of these tests are abnormal.
3- Tests for excess production of catecholamines:
Your physician – preferably an endocrinologist – may run the following tests to diagnose an excess production of catecholamines – adrenaline and noradrenaline:
- 24-hour urine for free catecholamines, metanephrines, and normetanephrines.
- Plasma free catecholamines.
Diagnostic test to diagnose if adrenal gland tumor is cancerous
The size of the tumor is a good indicator whether a tumor is benign or malignant.
Tumors less than 4.0 cm in size are generally benign. Tumors more than 4.0 cm carry a high risk for malignancy and therefore, need further evaluation, usually by a CT-guided needle biopsy.
Caution: Make sure that a tumor is not a catecholamine producing tumor before doing any biopsy or any other invasive procedure, because it can lead to a catastrophic event if it is a catecholamine producing tumor.
An adrenal tumor is typically non-cancerous. However, it deserves a through diagnostic evaluation for excess hormone production, preferably by an endocrinologist.