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Is a Lung Nodule Always Cancer?

April 15, 2024

Lung cancer is the second most common cancer in American men and women. Chest X-rays and CT scans reveal a lung nodule in up to half of adults. The good news is about 95% of lung nodules are benign and not a sign of lung cancer but it is important to get them evaluated.

Only one percent of chest CT scans show a solitary pulmonary nodule or small mass while a chest X-ray reveals nodules in about one in 500 patients. Fortunately, only three or four out of 100 lung nodules end up being cancerous. Hamartomas, or benign lung nodules, are the most common kind and account for about five percent of all tumors. Most benign lung tumors are asymptomatic, with no signs or symptoms. Often, they are found incidentally during other imaging procedures. 

A lung nodule is a small area of dense tissue found in the lungs during lung cancer screenings or imaging tests using computed tomography (CT) scans or X-rays. Because symptoms are so rare, more than 90% of lung nodules are found by accident during a routine check-up, a chest X-ray, or a CT scan. These growths may look like a shadow or spot on the lung. A tumor measuring an inch or less is called a nodule (which is smaller than a mass.) If you have a nodule in your lungs, it’s called a pulmonary nodule. A nodule or mass may also be referred to as a neoplasm or lung nodule.

Many things can cause benign lung nodules, including respiratory illnesses, infections scarring or some noncancerous condition that causes abnormal growth. Most lung nodules are scar tissue from past lung infections. Small, noncancerous lung nodules don’t usually require treatment outside of antibiotics or antifungal medications. Generally, benign tumors grow slowly, but they can sometimes stop growing or even shrink. Benign lung tumors don’t spread to other areas of your body.

The most common benign lung nodule is called a hamartoma. Hamartomas are clumps of normal connective tissue or cartilage, fat, and muscle that measure less than 2 inches. They show up on imaging as round, white spots in your lungs. Hamartomas account for about 75% of all benign lung tumors. Nearly 80% of this nodule type occurs in your lung’s connective tissues while the remaining 20% show up on the inside of your bronchial tubes. More men than women develop hamartomas by a 2:1 margin.

Some common indicators of benign lung nodules are that they are small in size, slow growing, have a higher calcium content, smooth, even shape and even colored. If a lung nodule is small and isn’t growing, it’s not likely to be cancer and may not need treatment. Your healthcare provider may look at past imaging tests to see if the nodule is new or changed, and might schedule you periodic CT scans, if necessary. 

Providers may be more worried about larger lung nodules and those that grow over time. If your nodule is large or is growing, you might need more tests to see if it’s cancer. This might include imaging tests, such as CT and positron emission tomography (PET) scans. Another test might be a procedure called a biopsy. This involves removing a piece of the nodule for testing in a lab.

Lung nodules should always be further evaluated for cancer. Because lung cancer treatment is more effective when it’s caught early, monitoring lung nodules early could save your life. If you have a lung nodule, the next step is to get a CT scan to see if the nodule is growing over time. The time between scans might range anywhere from a few months to a year, depending on how likely the doctor thinks that the nodule could be cancer. This is based on the size, shape, and location of the nodule, as well as whether it appears to be solid or filled with fluid. If a repeat scan shows that the nodule has grown, your doctor might also want to get another type of imaging test called a positron emission tomography (PET) scan, which can often help tell if it is cancer. If later scans show that the nodule has grown or has other concerning features, your doctor will want to get a sample to check it for cancer cells. 

Anyone can develop pulmonary nodules. A nodule is more likely to be cancer if you are a former or current smoker, older than 65, have a family history of cancer, received radiation to the chest or have had exposure to asbestos, radon or secondhand smoke. 

Quitting smoking is the best thing you can do to protect your lungs. But there isn’t anything you can do to prevent lung nodules. Fortunately, most lung nodules aren’t cancerous and don’t require treatment. A noncancerous lung nodule shouldn’t affect your quality of life.

If you have been diagnosed with a lung nodule, West Tennessee Healthcare’s Kirkland Cancer Center has a team of professionals who can help determine how best to proceed. To schedule an appointment, click here