An adrenal adenoma is otherwise known as an benign tumour which forms in the outer layer of the adrenal gland, which is found at the top of each of the body's kidneys. There are two types of adrenal adenoma, one type which produces hormones and one which does not. An adrenal adenoma which does not produce hormones is known as "non-functioning", however a "functioning" adrenal adenoma will produce excessive amounts of steroids which can lead to serious medical consequences.
Often, this condition will only be detected by accident, if the patient is being scanned for another purpose. For examples, patients who are receiving an abdominal CT or MRI scan to detect the presence of another condition, such as cancer, may have a lump detected on their adrenal gland. Studies have shown that up to 11% of patients receiving this type of CT scan will have an abnormal adrenal gland lump detected, however up to 80% of those will be non-functioning, or benign.
At the present time, the cause of adrenal adenomas are unknown. There is some speculation that they may occur because of certain gene mutations but this is as yet uncertain. There are also some medical conditions which are known to be associated with adrenal adenomas, including Carney complex, Beckwith-Wiedemann syndrome and multiple endocrine neoplasia type I. It is also known that those who are aged over 60 are more likely to develop an adrenal adenoma, and up to 6% of all people over this age suffer from the condition.
While a functioning adenoma will produce excessive steroid hormones, the majority of patients actually display very few symptoms, if any. In those patients who have developed an adenoma which is producing extremely high levels of this hormone, there will be some severe symptoms displayed. Too much cortisol can result in the development of Cushing's Syndrome, while excessive amounts of aldosterone is a cause of Conn's Syndrome. Another possible symptom is excessive hair growth and acne, which can be caused by too high levels of the male sex hormone testosterone. In some very rare cases, the patient may experience pain in the back or flanks as bleeding occurs into the adenoma.
Once a patient has been diagnosed with an adrenal mass, the first step is generally a referral to an endocrinologist which will be able to perform tests for certain related conditions such as Cushing's Syndrome and Conn's Syndrome. They will also check the patient for evidence of hair growth, acne and elevated blood pressure. The patient will generally undergo other scans, investigations and general examinations to determine whether other cancerous growths are present in the body. There are also several specific tests which will be performed to check hormone levels by the endocrinologist. These will include a 24 hour collection of urine for analysis for the presence of adrenaline and noradrenaline and several blood tests to check potassium levels, aldosterone and renin activity, the presence of excessive male hormones and also to test the levels of the female hormones progesterone and oestradiol. A low dose dexamethasone suppression test is also often carried out to see how well the body is able to control its cortisol secretion. Depending on the circumstances, the patients may also undergo a chest x-ray or an adrenal gland MRI scan.
There is, as yet, no evidence that this condition can be prevented, either by diet or lifestyle changes or through preventative medication.
Once a patient has been diagnosed with the functioning form of this condition, they will be referred for surgery. An adrenalectomy is an operation to surgically remove the affected adrenal gland, either through standard surgery or via keyhole surgery. To exclude the possibility of adrenal cancer in the patient, any adrenal mass which has been identified to have uncertain characteristics on an MRI scan, such as evidence of degeneration or bleeding, or a size greater than 3 cm, will be removed in an adrenalectomy procedure. This surgery holds no greater risk for the patient than any other form of abdominal surgery, although there are some risks associated with receiving a general anaesthetic. If the patient's growth is in their left adrenal gland, there is a possibility that the spleen may need to be removed as part of the operation. As the spleen is essential in protecting the body from certain bacterial infections, the patient may have to receive vaccinations before the procedure to guard against pneumococci and meningococci bacteria. If the adenoma is non-functioning, i.e. not producing hormones, and is under 3 cm in size, the patient will simply be monitored through annual scans to ensure that there is no growth or any development of suspicious associated symptoms.
Most patients who have been diagnosed with this condition can look forward to a good future outlook as long as their adenoma is non-functioning. If their adenoma is producing steroid hormones, their outlook is still excellent as long as the patient receives an early diagnosis and timely treatment.