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What is a lung nodule? A lung nodule, also called a pulmonary nodule, is a "spot" on the lungs that is seen on a chest X-ray or CT scan. If there is only one spot, it’s called a single (or solitary) lung nodule. A single lung nodule usually causes no symptoms. People find out they have an incidental lung nodule when they have a chest X-ray or CT scan done for another reason and as a surprise find there is an unexpected lung nodule.

How is a lung nodule found?

Chest CT scans are precise, specialized X-rays that are widely used to evaluate numerous medical issues including coronary artery disease (calcium score CT), chest pain worrisome for blood clots to the lungs (pulmonary embolus), chest trauma in accidents, etc. They are also used as a screening test for lung cancer in certain people who are at high risk for cancer. CT scans of the stomach are used to evaluate symptoms such as acute belly pain and kidney stones, extending up into the lower part of the lungs.

With the use of CT scans and common chest X-rays, numerous people are found incidentally to have lung nodules, usually referred to as "indeterminant" or undiagnosed lung nodules. Often doctors will tell patients that they have a spot, shadow or lesion on their lung when they mean a lung nodule.

Two doctors review lung scans for a lung nodule

How will my doctor know whether my lung nodule is cancer or not?

To determine whether a patient has cancer, their doctor will evaluate the risk factors. These lung nodule cancer risk factors include:

  • Nodule size and shape
  • Nodule location
  • Multiple nodules
  • Emphysema or lung fibrosis
  • Older age, male, Hispanic or African American
  • Strong family history
  • Tobacco or other inhaled carcinogens (asbestos, radon, pollution, etc.).
  • Second-hand smoke
  • Occupations such as miners and workers who use heavy metal or are exposed to radiation, etc.
  • Prior cancer
  • Dietary factors

Lung nodule causes

A lung nodule is rarely a sign of lung cancer. Instead, it is usually a result of inflammation caused by a past illness, infection or injury. What causes lung nodules? When lung tissue becomes inflamed, a small clump of cells (granuloma) may accumulate. Over time, a granuloma can calcify and form a noncancerous lung nodule.

Other possible causes of lung nodules include:

  • Benign lymph nodes in the lung tissue
  • Post-infection granulomas
  • Inflammatory nodules from rheumatoid arthritis, sarcoid, Wegener's granulomas
  • Prior scars from pneumonia
  • Active subacute infection
  • Benign lung tumors

Although anyone can develop pulmonary nodules, the risk is higher among current and former smokers as well as people who are older than 65, have a family history of cancer or have been exposed to radon, asbestos or secondhand smoke.

How are lung nodules diagnosed?

It is important to have a lung nodule evaluated by an expert at Moffitt Cancer Center. They will evaluate the lung nodule using clinical judgment as well as size, shape, location and other risk factors. The physician will then work with the patient to determine the best treatment plan.

To further evaluate a lung nodule that is more than 12 millimeters in diameter, a physician may order a:

  • Bronchoscopy. A physician guides a thin tube (bronchoscope) down the patient’s throat and into the lung, then uses a special surgical instrument attached to the end to retrieve a tissue sample from the nodule for analysis under a microscope.
  • CT scan-guided biopsy. To retrieve a tissue sample from a nodule on the outer part of a lung, a physician inserts a thin needle using real-time CT images for guidance.
  • Positron emission tomography (PET) scan. A safe radioactive chemical is injected before images are captured; the chemical will help illuminate any cancerous cells in the resulting images.

What are the chances a lung nodule is cancer?

If a doctor determines that there is a low chance that a lung nodule is cancer, he or she will likely monitor it closely with periodic chest CT scans. If it is a localized infection in the lung, the doctor may prescribe an extended course of antibiotics and repeat the chest CT scan.

If your lung nodule does not get bigger over time, it is most likely not cancer and the patient no longer requires repeat CT scans. However, if the lung nodule does get bigger over time, your doctor may recommend removing it by surgery.

If tests and a healthcare provider determine that the lung nodule is possibly cancer, then surgery is the best course of treatment. A PET scan (if not already done) is performed to help stage the possible cancer to see if it has spread anywhere away from the nodule. Also, lung function tests (pulmonary function tests) may be done by having the patient blow into a computerized machine that determines how strong the lung is. Depending on a patient’s medical history, they may need a heart evaluation before surgery.

However, if a patient has a probable small peripheral cancer but poor lung function or other severe medical problems that would make surgery too risky, a doctor may recommend obtaining a needle biopsy to verify the nodule is a cancer. A patient would then see a lung radiation oncology specialist for high-dose pinpoint radiation treatment (stereotactic body radiation therapy) of the cancer, which has a high chance of completely killing the cancer with minimal side effects.

Expert care from Moffitt's Lung Nodule Clinic

The lung nodule clinic at Moffitt Cancer Center is a part of the Lung Cancer Early Detection Center dedicated to managing patients with lung nodules for diagnosis and treatment recommendations. Millions of lung nodules are found yearly, and the majority are found incidentally. Most lung nodules are not evaluated or monitored by a healthcare professional. Of those that are followed, they are oftentimes not managed correctly. At Moffitt Cancer Center, we have a dedicated team of lung nodule experts, with years of experience following industry-standard lung nodule management.

If you have been diagnosed with a pulmonary nodule and would like to be evaluated in our dedicated Lung Nodule Clinic with an expert team, contact Moffitt Cancer Center to request an appointment by calling 1-888-663-3488 or completing our new patient registration form online. A referral is not required. When you turn to Moffitt, you will be a top priority of a cancer center that delivers nationally-ranked care in new and transformative ways.


American Cancer Society: Lung Nodules