More than 70 million chest X-rays and 80 million CT scans are performed each year in the United States. For nearly 50% of adults who get a chest X-ray or CT scan, the images reveal a concerning shadow in the lungs called a nodule.
“People are getting more chest X-rays and CT scans than ever for various reasons. And many of these people are surprised to find out they have a lung nodule,” says Drew Moghanaki, MD, an endowed professor and chief of UCLA Health’s Thoracic Oncology Service in the Department of Radiation Oncology.
A lung nodule is a small, round mass that appears as a white spot on an X-ray or CT scan. While most lung nodules are noncancerous (benign), they can still be concerning.
Dr. Moghanaki explains what you need to know about lung nodules:
When to worry about a lung nodule
Most lung nodules appear during unrelated imaging studies or lung cancer screening. Fewer than 5% of all lung nodules are lung cancer (malignant). But that doesn’t mean you should assume the mass is nothing, says Dr. Moghanaki.
“Lung nodules almost never cause any symptoms. Most people don’t feel them, so they’re easy to ignore,” he adds. “But in some situations, the lung nodule represents the early stages of a lung cancer that can be easily cured with surgery or targeted radiation therapy.”
Infections or other health conditions can also cause lung nodules. That is why you should have a medical expert, preferably a pulmonologist, assess a lung nodule as soon as it’s detected.
Benign lung nodule causes
Cancer isn’t the cause of most lung nodules. While some noncancerous (benign) nodules can be dismissed and left alone, others may require treatment. Reasons a benign lung nodule might develop include:
- Congenital (from birth) lung abnormalities, which may cause lung masses
- Fungal infection occurring when you breathe in fungal spores
- Inflammation associated with autoimmune diseases, such as rheumatoid arthritis or sarcoidosis
- Respiratory infections, such as pneumonia and tuberculosis
- Scar tissue, which can develop after long-term exposure to air irritants or pollutants
If a benign nodule is big enough, it may press on your airway and cause chest pain, breathing issues or unusual coughing. Let your doctor know if you experience those symptoms. In these rare cases, doctors may recommend surgery to remove the nodule.
Lung nodules and cancer
Lung nodules are more likely to indicate cancer for some people than for others. Your risk of lung cancer increases if you:
- Are 50 or older
- Have a family history of lung cancer
- Have a nodule or lung mass larger than 3 centimeters
- Received radiation therapy to the chest
- Smoke or ever smoked cigarettes
- Were exposed to asbestos, radon or other cancer-causing agents
Malignant lung nodules that occur without any symptoms tend to be early stage and highly treatable.
“Today’s treatments for lung cancer are safer and more effective due to advances in clinical research. More people with lung cancer are living longer and better lives than ever before,” Dr. Moghanaki says. “The detection of lung nodules is key to this success because it helps us diagnose lung cancer early enough to have the best chance for cure.”
If you develop a nodule on your lung …
If an X-ray or CT scan reveals a lung nodule, a pulmonologist can assess the nodule by considering:
- The appearance of the nodule on a CT scan: Physicians will study images of the nodule to determine its size, shape and density. Non-cancer nodules tend to be smaller, round and high in density.
- Whether the nodule changes over time: Nodules can grow slowly, so you may need follow-up scans in a few months. Let your physician know if you’ve had chest X-rays in the past so they can compare the images.
Nodules caused by infection may be treated with antibiotics or antifungal medication. Otherwise, your physician may recommend further evaluation for cancer or a watch-and-wait approach:
When does a lung nodule require a biopsy?
If your health care provider suspects cancer, they may recommend a lung biopsy — removal of a piece of the nodule for examination under a microscope. A biopsy can confirm whether the lung nodule is cancerous.
“If a lung nodule is cancerous, we have options,” Dr. Moghanaki says, “We now have a wide range of lung cancer treatments that are further increasing the cure rates for patients with stage 1, 2 or 3 lung cancer.”
If your physician believes a lung nodule is likely to be benign, they may recommend that you don’t get a biopsy to avoid any risk of complication.
Active monitoring of a lung nodule
Your health care provider may schedule active monitoring with periodic CT scans for smaller nodules with no immediate signs of growth. They might recommend a follow-up scan in three, six or 12 months. Nodules that don’t grow for two or more years are likely not cancer, although your doctor might continue monitoring them.
Call your doctor during that active monitoring period if you notice:
- Fever or chills
- Increased coughing or coughing up blood
- Shortness of breath or chest pain
- Unexplained weight loss
“Unfortunately, lung cancer remains a very common condition that is now affecting more women than men, and people who never smoked,” Dr. Moghanaki says. “For this reason, it’s important for all people with a lung nodule to be proactive about their health and make sure the lung nodule isn’t cancer. If it is cancer, we are here to help.”
