Adrenal adenoma

What is an adrenal adenoma?

The adrenal glands are tiny, triangle-shaped organs sitting on top of each kidney that produce essential hormones controlling your blood pressure, metabolism, and stress response. An adrenal adenoma is a benign (non-cancerous) tumor that grows in the outer layer of this gland.

Adrenal adenomas are classified by whether they are active and pumping out extra hormones:

• Non-functioning adenomas: the most common type (70% to 80% of cases). They do not produce any hormones, cause no symptoms, and are typically just monitored over time to ensure they stay stable.

• Cortisol-secreting adenomas: these overproduce the stress hormone cortisol. This can lead to Cushing’s syndrome, causing hidden health issues like high blood pressure, diabetes, and weakened bones (osteoporosis).

• Aldosterone-secreting adenomas (Conn’s adenoma): these flood the body with aldosterone, a hormone that regulates salt and water balance. This triggers severe high blood pressure and dangerously low potassium levels.

• Androgen-secreting adenomas: a very rare type that produces excess male sex hormones, causing physical masculinising changes in women. Unlike other functioning adenomas, tumours that secrete androgens are disproportionately likely to be malignant rather than benign, so these findings are investigated with particular care.

The distinction between a functioning and non-functioning adenoma is the most important clinical question after an adrenal adenoma is identified and is answered through hormonal blood testing.

Symptoms of adrenal adenomas

Non-functioning adenomas cause no symptoms. Functioning adenomas cause symptoms reflecting the specific hormone produced in excess.

Cortisol-secreting adenoma:

• Central weight gain with thin limbs

• Round, flushed face

• Purple stretch marks on the abdomen, thighs, and upper arms

• Easy bruising and thin skin

• Hypertension and diabetes

• Muscle weakness, particularly proximal limb weakness

• Osteoporosis and increased fracture risk

• Low mood, depression, and cognitive difficulties

• Subclinical cortisol secretion causes metabolic and cardiovascular consequences without the classic physical features above

Aldosterone-secreting adenoma:

• Hypertension, often severe and resistant to standard treatment

• Low potassium causing muscle weakness, cramps, and fatigue

• Increased thirst and urination from hypokalaemia impairing renal concentrating ability

• Headaches

Androgen-secreting adenoma (women):

• Excess facial and body hair (hirsutism)

• Acne

• Irregular or absent periods

• Deepening of the voice in severe cases

What causes adrenal adenomas?

The exact cause of most adrenal adenomas isn't fully understood, but a few factors are known to play a role:

• Somatic mutations in genes that regulate adrenal cell growth and hormone production, including PRKACA (in cortisol-secreting adenomas), KCNJ5 (in aldosterone-secreting adenomas), and CTNNB1, can drive both the autonomous hormone output and the benign cell growth.

• Age. Adrenal adenomas become significantly more common as people get older, with incidence rising from around 1% in the fourth decade of life to over 7% by the seventh.

• Genetic syndromes. Multiple endocrine neoplasia type 1 (MEN1) and familial adenomatous polyposis (FAP) both raise the risk of developing an adrenal adenoma.

• Obesity and metabolic syndrome. Both are linked to adrenal adenomas developing in the first place, and to autonomous cortisol secretion once one is present, which then worsens the metabolic syndrome further, a cycle that can reinforce itself over time.

How is an adrenal adenoma detected?

Adrenal adenomas are detected through abdominal imaging and characterised through hormonal blood testing. Both are essential.

Abdominal MRI Elfcare’s full-body MRI scans both adrenal glands to catch deep tissue abnormalities early. By measuring the tumour's size and picking up its fat content through specialised imaging (lipid-rich signals), the scan can usually identify the majority of benign adenomas, which tend to be lipid-rich. A minority are lipid-poor and don't show this signature; these get followed up with further imaging or monitoring to confirm they're benign. Size over 4 cm is one of several features, alongside imaging density, homogeneity, and growth over time, that prompts a more urgent evaluation.

Blood tests: Hormonal blood testing matters once an adrenal adenoma is identified, since imaging alone can't reliably tell functioning and non-functioning adenomas apart. Relevant markers in Elfcare's panel include:

• Cortisol: measures your morning stress hormone levels to check for overproduction.

• Aldosterone & renin ratio: screens for hormone-driven high blood pressure.

• Potassium: low levels support a diagnosis of aldosterone excess when present, though around half of people with an aldosterone-secreting adenoma have normal potassium, so a normal result does not rule it out.

• HbA1c and glucose: screens for hidden diabetes or insulin resistance, which excess cortisol can trigger.

• Cholesterol panel (total, LDL, HDL, triglycerides): assesses overall cardiovascular risk, which is useful context alongside a functioning adenoma diagnosis, since conditions like Cushing's syndrome are associated with adverse lipid profiles over time.

• Testosterone & DHEAS: measures male sex hormones to check for rare, masculinizing tumors.

• ACTH: a specialized brain hormone marker used to confirm if your adrenal gland is malfunctioning completely on its own.

Why early detection matters

Autonomous cortisol secretion, even at levels too low to cause the classic features of Cushing's syndrome, still raises the risk of hypertension, type 2 diabetes, osteoporosis, and cardiovascular events on its own. Catching autonomous cortisol secretion early means surgical treatment (adrenalectomy) can resolve the hormone excess before these consequences build up, and in many cases reverse damage that's already occurred.

Primary hyperaldosteronism from an aldosterone-secreting adenoma is the most common cause of secondary hypertension, yet the majority of affected patients are treated for years with multiple antihypertensive medications without the underlying cause ever being identified. Surgical removal of the adenoma improves or normalises blood pressure in most patients, and a substantial proportion are able to stop or significantly reduce blood pressure medication altogether. Every year of undiagnosed functioning adrenal adenoma is a year of preventable cardiovascular, metabolic, and skeletal damage accumulating silently.

How Elfcare can help

Elfcare's full body MRI images both adrenal glands directly, identifying adenomas and checking their lipid content through chemical shift sequences, which picks up the lipid-rich majority of benign adenomas. The lipid-poor minority need further imaging or follow-up to characterise fully; Elfcare arranges this as part of further diagnostics when needed. Our blood panel covers cortisol, potassium, HbA1c, lipids, and sex hormones, giving the initial hormonal assessment needed to pick up the most common functioning adenoma subtypes.

When an adrenal adenoma on MRI lines up with blood results showing autonomous hormone production, that's about as clear and actionable as a health check finding gets: a treatable cause of hypertension, diabetes, osteoporosis, or cardiovascular disease that may have gone unexplained for years.

If our MRI or blood tests identify an adrenal adenoma or related findings, we take care of further diagnostics or refer you to the appropriate specialist.