Lung Nodules

What Is a Lung Nodule?

A lung nodule is also called a pulmonary nodule or a spot on the lung. It is a small, round or oval shaped abnormal growth in your lung tissue. They measure up to 3 centimeters or about 1.25 inches in diameter. According to the American Thoracic Society (Opens in a new window), nodules are found in about 50% of adults. And while they are common, more than 90% of lung nodules are not cancerous.

Lung nodules are easy to find using chest X-ray or, more often, a chest CT scan. An EpicShare article (Opens in a new window) notes that about 30% of lung nodules are found by chance (incidentally) during CT scans or X-rays that were done for other reasons. However, they need to be examined and watched closely, because some could be a small lung cancer. Finding cancer early, when it is small and curable, is the goal of a lung cancer screening program.

Lung nodules that are less than 6 mm have a very low risk of being cancerous. Nodules that are 6 mm to 8 mm have a moderate risk. There is a significantly increased risk of cancer in nodules 8 mm to 10 mm in size. Larger nodules require advanced testing.

Lung Nodule Sizes

Types of Nodules

Lung nodules are either benign (noncancerous) or malignant (cancerous). Only about 4% of nodules found by screening are cancerous, according to the Lungevity (Opens in a new window) organization.

Benign Nodules. The vast majority of lung nodules are noncancerous. They usually form as a result of past illnesses, lung irritants or inflammation. The most common type is granulomas that form from past bacterial or fungal infections or from sarcoidosis or another autoimmune conditions. Noncancerous lung nodules usually don’t grow in size or grow slowly. If a nodule does grow rapidly, it is a sign that the nodule is caused by a recent infection or that it is inflamed.

Malignant Nodules. Malignant nodules can be primary lung cancer or can be metastatic (cancer that has spread from another part of the body). These require prompt evaluation, as cancerous nodules can grow quickly.

Lung Nodule Causes

• Benign tumors
• Cancer
• Congenital abnormalities like blood vessel clumps
• Enlarged lymph nodes
• Environmental exposures to irritants like tobacco smoke, asbestos or coal dust
• Infections like pneumonia, tuberculosis and histoplasmosis (fungal infection)
• Inflammatory conditions like rheumatoid arthritis and sarcoidosis
• Past inflammation
• Phlegm that gets impacted in tiny airways
• Scar tissue in the lungs from previous infections or old surgery scars

Nodules resulting from bacterial or fungal infections or local inflammation often go away or shrink completely on their own.

Risk Factors

• Age over 65 has the highest prevalence of lung nodules
• Exposure to secondhand smoke, radon gas, asbestos
• History of cancer, lung cancer or emphysema
• Infections and scar tissue from past or chronic infections
• Inflammatory or autoimmune diseases
• Smoking and tobacco use

Lung Nodule Prevention

It is not always possible to prevent developing a lung nodule. You can significantly reduce your risk of developing potentially harmful or cancerous lung nodules by taking these steps:

• Get screened for lung nodules/lung cancer if you have a smoking history.
• Minimizing exposure to asbestos, silica, talc, chemicals and other harmful toxins by wearing personal protective equipment.
• Quit smoking.
• Reduce exposure to pollution by staying inside or wearing an N-95 mask outside.
• Take steps to protect your lung health including healthy lifestyle.
• Test your home for radon.

Signs & Symptoms

Most lung nodules do not cause symptoms and are discovered during imaging tests performed for another reason. If symptoms appear, they can include:

• Chest pain
• Chronic cough
• Coughing up blood
• Fatigue
• Hoarseness
• Shortness of breath or wheezing

Diagnosis

Lung nodules are primarily identified through imaging tests and a patient’s smoking history.

Factors that may make a lung nodule more concerning include:

• Larger size. Nodules larger than 8 millimeters have a higher risk of being cancerous than smaller nodules.
• Growth over time. A nodule that increases in size on follow-up imaging may require additional testing.
• Irregular shape or borders. Nodules with uneven, spiculated (spike-like) or poorly defined edges may be more suspicious for cancer.
• Smoking history. Current and former smokers have a higher risk of lung cancer.
• Older age. The likelihood that a nodule is cancerous increases with age.
• Personal or family history of cancer. A history of lung cancer or other cancers may increase concern.
• Location in the upper lungs. Nodules found in the upper lobes of the lungs may have a higher risk of being cancerous.
• Certain imaging characteristics. Features seen on CT scans, such as density, calcification patterns and growth rate, help doctors determine the risk of cancer.

A lung nodule with one or more of these features does not necessarily mean cancer is present. Your doctor may recommend additional imaging, monitoring or a biopsy to determine whether the nodule is benign or malignant.

Imaging Tests

Chest CT Scan: A low-dose chest CT scan provides detailed images of the lungs. This is the gold standard way to identify suspicious nodules.

Chest X-ray: Sometimes a lung nodule is found by accident when a doctor is looking for something else. For example, if you fell and hurt your ribs, you might have an X-ray. If a lung nodule is found on an X-ray, your doctor will have the lung nodule evaluated.

PET CT Scan: This scan can evaluate a lung nodule, stage cancer, target and monitor treatment. It also can check if cancer has returned.

Diagnostic Procedures

Bronchoscopic Biopsy: A bronchoscopy is a small tube (bronchoscope) with a tiny video camera on the end. It is placed in the nose and guided into the lungs. Sometimes, a computer-assisted guidance system directs it to the lung nodule. A biopsy of the lung nodule is taken and examined by a pathologist.

CT-Guided Fine Needle Aspiration: During this type of biopsy, a thin needle is inserted through numbed skin and is guided to the lung nodule by CT scans. A tissue sample is collected through the needle and sent to pathology for analysis.

Lung Biopsy. A biopsy is a procedure that takes a tissue sample from the lung nodule. The sample is sent to a pathologist to examine under a microscope. A biopsy determines if the cells are normal, abnormal or cancer cells. It also can stage cancer and determine if it has spread and where it has spread.

Video Assisted Thoracoscopic Surgery (VATS): Sometimes, a lung nodule cannot be diagnosed with less invasive tests and surgery may be needed. During this minimally invasive procedure, a surgeon uses a small camera and specialized tools to remove the nodule or take a tissue sample. The tissue is then examined by a pathologist to determine if it is cancerous. Patients typically stay in the hospital after the procedure while they recover.

Treatment

Treatment for a lung nodule depends on what is causing it. Benign nodules do not require immediate treatment. Instead, your doctor may recommend follow-up CT scans to monitor the nodule for changes over time.

If a lung nodule appears suspicious for cancer or if follow-up imaging shows it has grown, additional imaging by PET scan or testing by biopsy, may be recommended to determine whether it is cancerous. If the nodule is diagnosed as lung cancer, treatment will depend on the type and stage of the cancer and may include surgery, radiation therapy, chemotherapy, targeted therapy or immunotherapy.

Lung nodules caused by an infection may be treated with antibiotics or antifungal medications. If the nodule is related to an inflammatory condition, such as sarcoidosis or rheumatoid arthritis, treatment will focus on managing the underlying disease.

Your doctor will recommend the treatment plan that is best for your specific diagnosis, overall health and risk factors.

Lifestyle Management

Adopting healthy lifestyle changes can protect your overall lung health and lower cancer risk.

• Avoid exposure to pollutants, dust, radon gas and other environmental toxins
• Eat a healthy diet
• Manage asthma, COPD and other respiratory conditions
• Quit smoking
• Stay active

Learn more at Living with Lung Cancer.

Clinical Trials

Clinical trials help determine new treatment options for diseases and conditions. Patients with lung nodules have access to clinical trials and should speak with their pulmonologist to determine which trials might work best for them.

When to See a Specialist

If you or a loved one has a newly found nodule, are worried about lung nodule growth, are experiencing symptoms or have a prior cancer history, it is important to see a pulmonologist who has experience diagnosing lung nodules.

As the leading respiratory hospital in the nation, National Jewish Health in Denver, Colorado, has pulmonologists with extensive experience diagnosing lung nodules. Ask your physician for a referral and use the button below to make an appointment.