Adrenal nodule

3 things to know first

1. It is usually not cancer. The vast majority of adrenal nodules are benign growths.
2. Size and appearance matter most. Small nodules with a benign look often need little or no follow-up.
3. It is commonly found incidentally. Adrenal nodules are seen on up to 5% of abdominal CT scans, and most people never knew they had one.

What it is

The adrenal glands are small, triangle-shaped glands that sit on top of each kidney. They produce hormones such as cortisol, aldosterone, and adrenaline.

An adrenal nodule is a small lump or growth in one of these glands. Many are benign adenomas, which are non-cancerous overgrowths of gland tissue. A minority are cysts, hemorrhages, or other benign lesions. Cancerous adrenal nodules are rare, especially when the nodule is small.

Why it appears on your report

Adrenal nodules are very common incidental findings on CT or MRI of the abdomen. Because the adrenal glands are scanned whenever the upper abdomen is imaged, radiologists often notice nodules even when the scan was ordered for something else, such as abdominal pain or kidney stones.

How serious is it

Most adrenal nodules are not serious. Risk is assessed by:

• Size: Nodules smaller than 4 cm are usually low risk. Larger nodules may need closer evaluation.
• Imaging features: Nodules that contain a lot of fat on CT are usually benign adenomas. Nodules with indeterminate features may need further testing.
• Hormone activity: Most nodules do not produce excess hormones. If hormone overproduction is suspected, blood or urine tests may be needed.

The risk of cancer is generally low, but your doctor will consider your history, especially if you have had cancer elsewhere in the body.

When to seek care urgently

Adrenal nodules themselves rarely cause emergencies. Seek urgent care if you have symptoms that can suggest a hormone surge, such as:

• Severe headaches with very high blood pressure
• Rapid heart rate with sweating and anxiety
• Sudden weakness or confusion
• Severe abdominal or flank pain

What usually happens next

1. Specialist review. A radiologist or endocrinologist will look at the imaging characteristics.
2. Possible hormone tests. If the nodule is 1 cm or larger, or has suspicious features, doctors may check hormone levels.
3. Follow-up imaging. Nodules with uncertain features may be rescanned in 6–12 months to see if they change.
4. Biopsy or surgery. These are rarely needed and are usually reserved for large, growing, or highly suspicious nodules.

A simple analogy

Think of the adrenal gland as a small hat sitting on top of each kidney. A nodule is like a tiny button sewn onto the hat. Most buttons are harmless decorations; only rarely does a button signal that the hat needs repair.

Further reading

• NHS — Adrenal gland tumours
• MedlinePlus — Adrenal nodules