Hearing that you have a growth in your lung can be terrifying, but for most people, it’s an unfounded fear. Less than 5 percent of these nodules turn out to be lung cancer.
A pulmonary nodule is a round, solid growth that forms inside your lung. It is always smaller than 3 centimeters. (A growth that is larger than that is called a pulmonary mass, which is more dangerous.)
Easy to miss
Because they’re too small to cause symptoms, nodules are usually found when a doctor orders a chest imaging study for lung symptoms caused by something else.
Only the largest nodules show up on an x-ray, so most are found on CT scans, where they appear as a dense white spot that radiologists sometimes call coin lesions. While the cause of most nodules is unknown, some can be attributed to benign tumors or cysts, diseases that cause lung inflammation, scar tissue from an old infection, or a lung abnormality from birth.
A very small number of pulmonary nodules are cancerous. To determine if yours should be biopsied (the only way to diagnose a malignant nodule), your doctor will assess the position, and size of the nodule, your personal risk for lung cancer, and the nodule’s growth over time.
- Position. Nodules that are located in the upper lung or have strands of tissue called spiculations radiating from them are riskier.
- Size. The smaller the nodule, the lower the risk. Those smaller than 0.6 centimeters have a less than 1 percent chance of being cancerous.
- Personal risk factors. Older age, a history of smoking, a family history of lung cancer, having a long-term lung disease or another cancer, and exposure to chest radiation therapy or toxic substances like dusts, metals, fumes, or asbestos increase the risk of cancer.
- Growth. A nodule that increases in size over time is usually biopsied.
If your nodule was present on a previous CT scan or chest x-ray, the size can be compared to the recent imaging study. If you don’t have a nodule on an old imaging study, your doctor may take a wait-and-see approach and schedule a chest imaging study in a few months.
If your doctor thinks you are at high risk for lung cancer, you may need an imaging study called a PET scan, which gives more detailed images than a CT scan.
If your nodule is high risk or a PET scan finds changes that suggest cancer, your doctor will perform a biopsy.
A biopsy may be taken through a tube placed down your throat and windpipe into your lung, called a bronchoscopy. If the biopsy is near the outside of your lung, a needle may be placed through your skin and into your lung to get a needle biopsy. If a nodule is very suspicious or difficult to reach, open surgery may be done to remove it (excisional biopsy).
Though lung cancer is always dangerous, these nodules are usually found at an early stage of lung cancer. Surgery may be able to remove the whole cancer, increasing the possibility of a cure.