A lung nodule is a type of abnormal growth that can occur in the lung. Lung nodules can occur in either lung, and patients may have more than one nodule. Lung nodules can be detected on CT scans or X-rays.
The average size of a lung nodule is typically under 10mm, which is less than half an inch. Larger nodules are associated with a higher risk of lung cancer, but with regular CT scans, lung cancer can often be caught in an early stage and treated. The majority of cases of lung nodules, roughly 95%, are non-cancerous.
Lung nodules may also be referred to as pulmonary nodules or spots on the lung.
Lung nodules can have a variety of different causes.
One of the most common causes of lung nodules is a previous illness or infection. Previous lung infections such as tuberculosis can cause scar tissue in the lungs. Fungal infections such as histoplasmosis or blastomycosis also present very similarly to lung nodules. Additionally, certain types of cancer such as kidney cancer has the potential to spread to the lungs, resulting in lung nodules.
Individuals who smoke or are regularly around other irritants in the air are more likely to develop lung nodules and are at a greater risk for developing lung cancer.
Symptoms of lung nodules typically vary by the size and location of the nodules. Smaller nodules may not cause symptoms at all. Larger nodules may cause a variety of symptoms, including:
Treatment for lung nodules is often personalized based on the size of the nodules as well as any other risk factors that may contribute to a patient developing lung cancer.
The vast majority of patients undergo active surveillance, where they receive regular CT scans for 1-2 years after diagnosis to determine if the nodule is growing. Typically if there is no growth after 2 years, there is much less risk for that nodule to be cancerous. For these patients, a lung biopsy is typically not recommended, due to increased risks from performing the procedure compared to watching and waiting.
For patients whose lung nodules have grown, a bronchoscopy may be performed. In this procedure, a tube is inserted through the throat into the lungs and is used to get a sample of the lung nodule. For nodules on the outer part of the lung, it is also possible to insert a thin needle through the chest to get a sample. After the sample is tested and if it is found to be cancerous, it can be removed through an incision in the chest.
The majority of patients with lung nodules will have either no or minimal health complications, although it is suggested to receive additional CT scans over time to see if the nodule is growing. Roughly 5% of lung nodules turn out to be cancer, which can have more significant complications if not treated early.
The majority of lung nodule cases are non-cancerous and do not cause symptoms. However, call your provider right away if you are experiencing symptoms such as: