Lung nodules have been in the news this week, after Pope Leo XIV announced that he will undergo surgery to remove a small nodule in his lung that was found at a very early stage. Many people have since asked what a lung nodule is, whether it always means cancer and what should happen when one is found.
Being told that a scan has shown a “spot” or “nodule” on the lung can be worrying. The reassuring news is that most lung nodules are not cancer. At the same time, a lung nodule should never be ignored. Some nodules are early lung cancers, and finding them at this stage gives the best chance of successful treatment.
Dr Dionysis Papadatos-Pastos, a consultant medical oncologist in London specialising in lung cancer, mesothelioma and thymic tumours, explains what lung nodules are, what can cause them, how they are assessed in the UK and why expert advice matters.
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Topics CoveredWhat Is a Lung Nodule?
A lung nodule is a small, rounded area of tissue in the lung that looks denser than the surrounding lung on a scan. Nodules are usually up to about three centimetres across; anything larger is generally described as a mass. Most people with a lung nodule have no symptoms at all.
Nodules can look different on a CT scan. Some are solid, some appear hazy (often called “ground-glass” nodules) and some are part-solid, with both features. Their size, shape, edges and appearance all help doctors judge how likely they are to need further tests.
Many nodules are found by chance, on a CT scan carried out for another reason, such as chest pain, an injury or a scan of the heart or abdomen. Others are found through lung cancer screening, which the NHS is rolling out across England for people aged 55 to 74 who smoke or used to smoke.
A Lung Nodule Is Not Always Cancer
Most lung nodules are benign, which means they are not cancer. The lungs react to infection, inflammation and injury throughout life, and many of these reactions leave small marks that show up on a scan. Possible causes include:
- **Granulomas**: small areas of healed inflammation, often left behind by a past infection such as tuberculosis (TB) or a fungal infection.
- **Hamartomas**: benign growths made of normal lung tissues, such as cartilage and fat, arranged in an unusual way.
- **Intrapulmonary lymph nodes**: normal lymph nodes that sit within the lung tissue.
- **Rheumatoid nodules**: nodules that can occur in people with rheumatoid arthritis.
- **Sarcoidosis**: an inflammatory condition that can cause nodules in the lungs and lymph glands.
- **Scarring**: areas of scar tissue from previous infection, inflammation or injury.
Some nodules, however, are cancers or may become cancers over time:
- **Primary lung cancer**: a cancer that starts in the lung, including early forms of adenocarcinoma that can appear as ground-glass nodules.
- **Carcinoid tumours** (slow growing tumours): a type of neuroendocrine tumour that can start in the lung.
- **Metastases**: cancer that has spread to the lung from another part of the body.
Because benign and cancerous nodules can look similar on a single scan, the cause cannot always be known straight away. This is why careful assessment matters.
Why a Lung Nodule Should Never Be Ignored
When a lung cancer is found as a small nodule, it is usually at an early stage, before it has had the chance to spread. At this stage it can often be treated with the aim of cure. Once lung cancer causes symptoms, it is more often at a later stage, when treatment becomes more complex.
Some features make a nodule more likely to need closer attention: a larger size, an irregular or spiky outline, growth over time and a solid part within a hazy nodule. Personal factors also matter, including age, current or past smoking, a family history of lung cancer, past exposure to asbestos and a previous cancer elsewhere in the body. Our guide to lung cancer risk factors explains these in more detail.
A nodule mentioned in a scan report can sometimes fall between appointments or services, particularly when the scan was done for a different reason. If you have been told about a nodule, it is worth making sure that you know who is responsible for following it up, what the plan is and when the next scan or appointment will be.
How Lung Nodules Are Assessed in the UK
In the UK, doctors follow the British Thoracic Society guidelines on pulmonary nodules. The approach depends on the size and appearance of the nodule and on each person’s individual risk.
**Very small nodules** that are very unlikely to be cancer may need no further tests.
**CT surveillance** is often recommended for nodules that are small or have a low risk. A repeat CT scan after a set interval shows whether the nodule is stable, shrinking or growing. Doctors can measure the volume of a nodule precisely and work out how quickly it is changing. Hazy, ground-glass nodules are often followed for longer, because when they are cancers they tend to grow slowly.
**Risk calculators** combine the features of the nodule with personal risk factors to estimate how likely it is to be cancer. This helps decide whether to watch the nodule or investigate further.
**A PET-CT scan** may be used for larger or higher-risk nodules. It shows how active the nodule is, which can help distinguish cancer from benign causes, although it is less reliable for very small or ground-glass nodules.
**A biopsy** takes a small sample of tissue for analysis, either through a thin needle guided by CT or through a bronchoscope. Our article on lung cancer biopsy explains the different types and what to expect.
Decisions about lung nodules are best made by a specialist multidisciplinary team (MDT), where respiratory physicians, radiologists, surgeons and oncologists review the scans together and agree the safest plan.
Treatment and Management Options
Many people with a lung nodule need no treatment at all. Depending on the findings, the options include:
- **Monitoring with CT scans**, when the risk is low, to confirm that the nodule remains stable.
- **Surgery to remove the nodule** (minimally invasive procedures such as video assisted thoracoscopy or robotic surgery can be considered to reduce recovery time), when cancer is suspected or confirmed. Removing the nodule both confirms the diagnosis and treats it.
- **Stereotactic ablative radiotherapy (SABR)**, a highly precise form of radiotherapy, for people who are not able to have surgery or prefer not to.
- **Treatment of the underlying cause**, when a nodule is due to a condition such as infection or inflammation.
If a nodule proves to be lung cancer, our guide for people who have just been diagnosed with lung cancer explains the next steps.
Why Expert Assessment Matters
Lung nodules are common, and most of them turn out to be harmless. The skill lies in identifying the small number that need action, without exposing everyone else to unnecessary tests and worry. This balance is best achieved with experienced specialists who look at the whole picture: the scans, the person’s history and their preferences.
A private specialist consultation can complement NHS care. It offers rapid access to an experienced opinion, dedicated time to explain the scan findings and the options, and the reassurance of MDT input. It can also be a valuable second opinion when a report mentions a nodule and the next steps are not clear. Bringing previous scans and reports allows nodules to be compared over time, which is often the key to the right decision.
Conclusion
Finding a lung nodule can be unsettling, but it is important to keep it in perspective. Most nodules are benign, and many need nothing more than a follow-up scan. However, a lung nodule should never be ignored. A clear plan, agreed by specialists, makes sure that the few nodules that are early cancers are found at the stage when treatment works best.
If a scan has shown a lung nodule, Dr Papadatos-Pastos offers in-person and virtual consultations to review the findings and discuss the next steps.
Support and Follow-Up Care
Dr Papadatos-Pastos and his team provide ongoing support beyond medical treatment.
Patients receive clear communication, psychological care and access to nutrition, physiotherapy and symptom-management services.
Regular follow-up ensures early detection of recurrence and long-term wellbeing.
Book a Consultation
If you or someone close to you has been diagnosed with lung cancer, early consultation with a specialist can make a real difference. Appointments are available at several London clinics.
Faq
Answers to Common Questions
Patients and families often have similar questions when a scan shows a lung nodule. The answers below address the concerns that come up most often.
No. Most lung nodules are benign and are caused by things such as old infections, inflammation or scarring. However, some nodules are early lung cancers, which is why every nodule should be assessed and followed up according to a clear plan.
Doctors look at the size of the nodule, its shape and outline, whether it contains a solid part and, most importantly, whether it grows over time. Personal factors such as age, smoking history, asbestos exposure and a previous cancer are also taken into account.
Not always. Many nodules can be safely monitored with CT scans. A biopsy is usually considered when a nodule is larger, growing or looks suspicious, and when the result would change the treatment plan.
This depends on the type of nodule. Solid nodules are often monitored for a shorter period to confirm that they are stable, while hazy, ground-glass nodules may be followed for several years because they tend to change slowly. Your specialist team will explain the plan for your nodule.
Yes. Nodules caused by infection or inflammation can shrink or disappear on a follow-up scan. This is one reason why a repeat CT scan is often recommended before any invasive tests.
It is natural to feel anxious, but most nodules are not cancer. The most important step is to make sure the finding is not ignored: ask who will follow it up, what the plan is and when the next scan will be. If you are unsure, a specialist opinion can provide clarity and reassurance.
