What a lung nodule is

Lung nodules are abnormal areas of growth seen on a chest X-ray or CT scan. By definition, any lesion less than 3 cm across is termed a nodule, and nodules can be single or multiple. With the widespread use of CT scans, small spots in the lung are being found in people who never had a lung symptom.

The vast majority are harmless, often the scar of an old infection.

Why there are usually no symptoms

Most lung nodules lie deep within the lung, away from the blood vessels and airways that would produce symptoms. Many of the nodules referred to our clinics are incidental findings on CT scans done for other purposes, such as a CT coronary angiogram to assess the heart. Nodules can sometimes be seen on a chest X-ray, but a CT scan is far superior for evaluating them.

What makes a nodule more or less worrying

The size, shape and appearance of the nodule, how it behaves over time, and your own risk factors help us decide what to do. Size matters in the risk of cancer, typically once a nodule is larger than 5 mm, but there are many other factors. The shape, for example a spiculated nodule with spiky edges, is more concerning for cancer, and risk factors such as smoking or a family history of cancer are all important in deciding the best next step.

Growth over time is another important factor. However, slow-growing infections can have a very similar appearance and can also grow between scans. Every patient therefore has to be carefully reviewed to decide on the next step.

How we investigate and follow up

Many nodules need nothing more than a repeat scan to confirm they are stable. A few need further tests such as a PET scan, a biopsy or removal. Follow-up can range from simple reassurance to biopsy or surgical removal. Guidelines typically consider a nodule that has remained the same for three to five years as stable, but individual patients do not always fall neatly within guidelines, and there is no one-size-fits-all management for lung nodules. In most cases low-dose CT scans can be used to monitor a nodule, reducing the overall lifetime exposure to radiation from CT scanning.

A PET-CT scan can help us decide on the next step. However, a normal PET-CT does not rule out early cancer, and a PET-CT can also be positive in infections, so not every patient with a nodule needs one. The nodule's characteristics and the individual patient's circumstances determine whether it is needed.

Whether a biopsy is needed, and which kind, depends on the size and location of the nodule and on patient factors such as whether certain procedures can be tolerated. A bronchoscopy is often a day procedure performed in the endoscopy suite: a scope is passed into the airways under moderate sedation, with minimal risk in most cases. A CT-guided lung biopsy usually needs an inpatient stay afterwards to monitor for complications.

Neither ignore nor panic

Finding a nodule should neither be ignored nor be a cause for panic, and the right plan is the one that is tailored to you.

Lung and Respiratory Conditions: A Patient Guide · Lung Cancer Screening: Where Are We Now? · The Aeden Physicians

Frequently Asked Questions

Are lung nodules usually cancer?

The simple answer is no. There is no need to panic when you have been told that you have a lung nodule, but it is just as important not to ignore a nodule without having it evaluated.

Does a lung nodule always need a biopsy?

No. Many lung nodules can be monitored with interval CT scans, and in most cases low-dose CT scans can be used, reducing the overall lifetime exposure to radiation.

What decides how a lung nodule is managed?

The size, shape and appearance of the nodule, how it behaves over time, and your own risk factors help us decide what to do. Every patient has to be carefully reviewed to decide on the next step.