Information about lung nodules

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What is a lung nodule?

A lung nodule is a small growth in your lung. On a CT scan or chest x-ray it looks like an area of roundish shadowing less than 3cm (about 1 inch) across. It does not cause any symptoms.

How are lung nodules diagnosed?

Nodules are sometimes seen on a chest x-ray but in most cases they are too small and are only seen when the person has a CT scan. Lung nodules are often found when the person is having a CT scan for another reason.

It is not always possible to know what the cause of a nodule is from the CT scan alone. Because nodules are usually small, a biopsy (a test performed to obtain a sample of the nodule) may be very difficult. Instead we keep an eye on the nodule by repeating the CT scan after a certain amount of time to see whether it grows or changes shape.

Why do lung nodules occur?

• Lung nodules are very common.
• About 1 in 4 older people who smoke or used to smoke have nodules that are seen on a CT scan. People who have never smoked may also have nodules that are seen on a CT scan.
• The majority of lung nodules are benign (non cancerous).
• Some nodules are tiny areas of previous inflammation in the lung, or areas of scarring from previous lung infections.
• Some are normal lymph glands in the lung.
• They are very common in people who have had TB (Tuberculosis) and can occur in people who have had other conditions such as rheumatoid arthritis.

In a small number of people the nodule can be a very early lung cancer or occasionally a secondary cancer that has spread from elsewhere in the body.

Benign (non cancerous) nodules grow very slowly, or may not grow at all. Malignant (cancerous) nodules will eventually grow although this can happen very slowly over months or years.

What happens next?

Lung nodule on scan

Review by lung team: if the nodule looks benign or has been there for a long time you don’t need any further investigations.

Repeat scan usually in 3 months from first scan: may be discharged at this point.

Repeat scan every year for a number of years if required: PET-CT scan or further tests if the nodule grows.

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