An Adrenal Nodule Was Found on Your CT Scan. Now What?

By: Mehdia Amini, MD

An adrenal incidentaloma is an adrenal mass discovered unexpectedly on a CT scan or MRI performed for another reason. It is a common finding, and most adrenal nodules are benign. Still, an adrenal mass should be evaluated because there are two important questions to answer:

1. Does it look benign?
2. Is it producing excess hormones?

What Does the Adrenal Nodule Look Like?

The first step is reviewing the imaging characteristics of the mass. A benign adrenal adenoma often has a characteristic appearance on CT. Radiologists evaluate its density, as well as whether the lesion looks uniform throughout rather than containing irregular or distinctly different areas. A uniform adrenal mass with low density is strongly suggesting of a benign adrenal adenoma.

A lesion that is more dense, irregular, contains different-appearing areas, enlarges over time, or is unusually large may require additional evaluation with dedicated adrenal imaging or follow-up. Size matters, but size alone does not determine whether an adrenal mass is concerning.

Could the Nodule Be Producing Hormones?

The next question is whether the adrenal mass is producing hormones independently. The main conditions endocrinologists evaluate for are cortisol excess, primary aldosteronism, and pheochromocytoma.

Cortisol Excess

Some adrenal adenomas produce excess cortisol. Classic Cushing syndrome is rare in patients with incidentally discovered adrenal nodules. More often, when abnormal cortisol production is present, it is mild and may occur without the classic appearance people associate with Cushing syndrome.

This is called mild autonomous cortisol secretion. Instead of dramatic symptoms, it may be associated with conditions such as:

• Hypertension

• Diabetes or worsening glucose control

• Osteoporosis or fractures

• Central weight gain

• Increased cardiovascular risk

Cortisol production can be evaluated in several different ways depending on the clinical situation. The important point is that excess cortisol production may be subtle and may not cause obvious symptoms.

Aldosterone and High Blood Pressure

Adrenal nodules can occasionally produce too much aldosterone, a hormone involved in blood pressure and potassium regulation.

This condition is called primary aldosteronism.

It may be suspected in someone with an adrenal nodule who also has hypertension, particularly if the hypertension developed at a younger age, has been difficult to control, or is associated with low potassium levels.

Identifying primary aldosteronism matters because treatment can often be directed specifically at the underlying hormonal problem.

Pheochromocytoma

A pheochromocytoma is a rare adrenal tumor that produces catecholamines such as epinephrine and norepinephrine.

Symptoms may include episodes of:

• Severe or fluctuating hypertension

• Palpitations

• Headaches

• Sweating

• Tremor

Pheochromocytomas are uncommon, but they are important to recognize because their evaluation and treatment are very different from those of a typical adrenal adenoma. Not every adrenal incidentaloma requires testing for pheochromocytoma. The appearance of the lesion on imaging helps determine whether testing is necessary.

Could It Be Cancer?

Most incidentally discovered adrenal nodules are not cancer. Adrenocortical carcinoma is rare, particularly when a nodule has reassuring imaging characteristics. Concern increases when a mass is larger, has a higher density on CT, grows substantially, or has irregular or otherwise suspicious features.

A patient’s medical history also matters. In someone with a known cancer elsewhere in the body, an adrenal lesion can occasionally represent a metastasis rather than a primary adrenal tumor.

Even more rarely, adrenal abnormalities can be caused by lymphoma, infection, hemorrhage, or other infiltrative diseases. These possibilities become more relevant when the imaging does not look like a typical adenoma, both adrenal glands are involved, or the patient’s overall medical history raises concern for another process.

These diagnoses are uncommon, but they are part of the reason an adrenal mass should be properly characterized.

Does Every Adrenal Nodule Need Surgery?

No. Most adrenal incidentalomas do not require surgery.

Surgery is generally considered when an adrenal mass: produces clinically significant excess hormones, has concerning imaging characteristics, demonstrates significant growth, or raises concern for malignancy.

A clearly benign, nonfunctioning adrenal adenoma often requires no surgery and, in many cases, no ongoing imaging surveillance.

Do Adrenal Nodules Need to Be Followed for Years?

Not always. Older recommendations often led to repeated scans and annual hormone testing for as long as five years. Current guidance has moved away from that approach. If an adrenal nodule has clearly benign imaging characteristics and the initial hormonal evaluation is normal, routine yearly CT scans and hormonal testing for five years are generally not necessary.

When the imaging is not completely definitive, repeat imaging may be performed after approximately 6–12 months to confirm that the lesion is stable.

In selected patients, particularly when there is concern for mild cortisol production or changes in related medical conditions, cortisol function may be reassessed over the following several years. Follow-up should therefore be based on the characteristics of the individual adrenal nodule and the patient’s clinical picture rather than an automatic five-year testing schedule.

What About a Biopsy?

Adrenal nodules are generally not routinely biopsied.

Biopsy cannot reliably distinguish a benign adrenal adenoma from adrenocortical carcinoma and may be dangerous if the lesion is an unrecognized pheochromocytoma.

It is mainly reserved for selected situations - for example, when someone has another known cancer and determining whether an adrenal lesion represents metastatic disease would change treatment.

Conclusion

Most adrenal incidentalomas are benign and will never cause a health problem.

The purpose of an endocrine evaluation is to determine whether the mass has reassuring imaging characteristics, whether it is producing excess hormones, and whether anything in the patient’s medical history suggests that the finding deserves closer evaluation.

If an adrenal nodule was found on your imaging and you are unsure whether it has been fully evaluated, a focused endocrine review can help determine what testing is actually needed and what can safely be left alone. Schedule a consultation with Dr. Mehdia Amini at Evora Women’s Health, for a comprehensive endocrine evaluation.