Benign Lung Tumors

A benign lung tumor is an abnormal rate of cell division or cell death in lung tissue or the airways that lead to the lungs. It isn’t cancerous. Types include hamartomas, adenomas and papillomas. In most cases, benign lung tumors don’t require treatment, but a healthcare provider will recommend monitoring them for changes.


What are benign lung tumors?

Hearing the word “tumor” may naturally cause fear or panic. But a tumor is simply an abnormal buildup of tissue that occurs when cells divide too quickly or don’t die off as they normally should. A lung tumor is a tumor that occurs in the lung tissue itself or in the airways that lead to the lungs. Your airways include your:

Lung tumors can either be cancerous (malignant) or noncancerous (benign).

If a healthcare provider tells you that you have a lung tumor and it “looks like it’s benign,” what does that mean? Should you have concerns?

When compared to malignant tumors, benign lung tumors:

  • Aren’t cancerous, so they won’t spread to other parts of your body.
  • Grow slowly or might even stop growing or shrink.
  • Aren’t usually life-threatening.
  • Usually don’t require removal.
  • Can expand and push against nearby tissues but won’t invade, destroy or replace other tissues.

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Are there different types of benign lung tumors?

Yes, there are several types of benign lung tumors. Tumors that are generally larger than 3 centimeters (1.2 inches, or about two aspirin tablets) in diameter are masses. Tumors that are 3 centimeters or fewer in diameter are nodules. If a nodule forms in your lungs, it’s a pulmonary nodule. “Pulmonary” means something relates to, affects or occurs in your lungs.

Types of benign lung tumors and nodules include:


Hamartomas consist of “normal” tissues, such as cartilage, connective tissue, fat and muscle, but in abnormal amounts. They’re usually less than 4 cm in diameter and appear in chest X-rays as a round growth that looks like a coin. But in about 15% of cases, they may look like fluffy wool or popcorn.

Hamartomas usually stay within a limited area and aren’t likely to press against nearby tissue.

Bronchial adenomas

Adenomas are another common type of benign lung nodule. They grow in the bronchi and the mucus glands or ducts of the windpipe.


Papillomas are a less common type of benign lung tumor. They grow in the bronchial tubes, sticking out from the surface area. There are three types of papillomas:

  • Squamous papillomas. One or more squamous papillomas can occur in children and adults. They result from a human papillomavirus (HPV) infection. HPV is the same virus that causes warts and certain sexually transmitted infections (STIs). Squamous papillomas have the potential to become malignant.
  • Glandular papillomas. Glandular papillomas are less common than squamous papillomas. They develop in larger airways than squamous papillomas. They occur in all ages but mostly affect adults. Glandular papillomas almost always appear as one centrally located nodule. Healthcare providers and medical researchers aren’t sure what causes them.
  • Mixed squamous and glandular papillomas. These papillomas contain a mix of squamous and glandular papilloma tissue. There are only a few reported cases of mixed squamous and glandular papillomas. They can potentially become malignant because the squamous cells can change over time.

Other benign lung tumors

Other rare benign lung tumors include:

  • Chondromas. A chondroma consists of cartilage. It generally forms in your hands or feet but may also develop in your ribs, upper arms or thighs.
  • Fibromas. A fibroma consists of fibrous tissue. It can form anywhere in your body.
  • Neurofibromas. A neurofibroma consists of connective tissues. It develops along your nerve cells.
  • Lipomas. A lipoma consists of fatty tissue. It’s very common and grows just below your skin anywhere on your body.

How common are benign lung nodules?

Pulmonary nodules are fairly common. Healthcare providers see them in about 1 in every 500 chest X-rays. They find them in 80% to 90% of all CT (computed tomography) scans. They find nodules 6 millimeters or larger in 15% to 20% of CT scans. At least 60% of the pulmonary nodules that providers see in chest X-rays are benign, and 99% of those in chest CT scans are benign. If you’re over 50 and smoke, there may be a higher chance of nodules appearing on a CT scan of your chest.

What is the most common benign lung tumor?

Hamartomas are the most common type of benign lung nodule. They account for about 55% of all benign lung tumors and about 8% of all lung tumors.


Symptoms and Causes

What are the symptoms of a benign tumor in the lungs?

Most people don’t have any symptoms of benign lung tumors. Healthcare providers discover more than 90% of nodules by accident while performing a chest X-ray or CT scan for some other condition.

If you do have symptoms, they may include:

What causes benign lung nodules or masses?

There are many possible causes of benign lung nodules or masses. These causes may include:

In some cases, there are no known causes.


Diagnosis and Tests

How are benign lung nodules diagnosed?

Healthcare providers usually discover benign lung nodules and tumors during a chest X-ray or CT scan for another condition. The appearance of the nodule on the CT scan is often enough for a provider to determine that it’s benign. If a provider can’t determine the cause of a nodule from a CT scan, they may perform a bronchoscopy to take a closer look at the nodule or mass and get a tissue sample (biopsy). During a bronchoscopy, the provider slides a scope with a camera at the end down your throat and into your lungs. You’ll get a sedative before the procedure, so you’re unaware of what’s happening.

The provider may get a tissue sample during the bronchoscopy. Or they may get a tissue sample by using a CT scan to insert a needle into the mass to extract a small amount of tissue.

A provider will also use the following information to make a diagnosis:

  • Nodule size. The provider may chart the growth rate of your nodule. The smaller the nodule, the more likely it is to be benign. Benign nodules also grow very slowly, if they grow at all. Cancerous nodules, on average, can double in size every four months or fewer.
  • Nodule content and shape. Another way to tell the difference between a benign lung nodule and a malignant one is to see if there’s calcium within it. If calcium is present, it looks white on a CT scan. Benign nodules may have calcium in them, whereas malignant nodules usually don’t. They’re also normally smoother and have a more regular shape. Malignant nodules typically have irregular shapes and rougher surfaces.

Management and Treatment

How do you treat a benign nodule or mass in the lungs?

In most cases, benign lung nodules and masses don’t require treatment. A healthcare provider will recommend taking a series of X-rays and CT scans over a period of months to years to watch for any changes in tumor size or features.

Does a benign lung tumor have to be removed?

No, a healthcare provider doesn’t have to remove a benign tumor. They may only recommend removing a benign lung tumor if it changes.

When should a benign lung nodule be removed?

A healthcare provider may recommend a biopsy or surgery to remove the tumor if they aren’t certain that it’s benign or harmless, or if:

  • You smoke or have a high risk of cancer.
  • You have difficulty breathing or other symptoms.
  • Tests show that cancer may be present.
  • The nodule continues to grow.

How soon after treatment will I feel better?

You should avoid heavy lifting and strenuous activities for about a week if you have a biopsy or surgery to remove a benign lung tumor.


Can benign lung tumors be prevented?

Benign lung tumors are usually harmless. A healthcare provider can tell you what to expect if you have an underlying condition that causes benign lung tumors to form.

Outlook / Prognosis

What can I expect if I have been diagnosed with a benign lung tumor?

If you and a healthcare provider agree to simply monitor (“watch and wait”) your lung tumor, it’s important that you schedule regular follow-up appointments. Be sure to attend every appointment. If you have to miss an appointment, be sure to reschedule.

If you have surgery to remove a benign lung tumor and a provider completely removes it, you usually don’t need additional treatment.

Living With

How do I take care of myself?

Though benign lung tumors don’t usually cause major health problems, the best thing you can do is be aware of changes in your body. Talk to a healthcare provider if you develop symptoms that affect your breathing or cause long-lasting (chronic) coughing. You should also schedule an appointment with a provider if you notice new lumps or bumps that appear to grow.

If you smoke or vape, it’s a good idea to quit.

When should I see a healthcare provider?

Call a healthcare provider if you:

  • Develop a cough, start to cough more or cough up blood.
  • Develop new symptoms, including shortness of breath, fever, chills or chest pain.
  • Have unexplained weight loss of 10 pounds or more.

What questions should I ask a healthcare provider?

Questions to ask your provider include:

  • How do you know I have a lung tumor?
  • How do you know my lung tumor is benign?
  • What kind of benign lung tumor do I have?
  • Do I need any other tests?
  • Do I need treatment?
  • How often should I schedule follow-up appointments?
  • Should I schedule an appointment with a pulmonologist?

A note from Cleveland Clinic

It can be scary hearing that you have a “spot on your lung.” Feeling anxious or nervous is normal, even if there’s only a small chance you have lung cancer. But most small nodules are benign and aren’t cancer. Even in the worst-case scenario — the nodule turns out to be cancer — it’s likely at an early stage and very treatable. Most small nodules don’t cause noticeable symptoms, so a healthcare provider will want to monitor your benign lung tumor with imaging tests over the next few months or years to ensure it’s not growing or changing. Reach out to a provider if you have any questions or concerns.

Medically Reviewed

Last reviewed by a Cleveland Clinic medical professional on 10/19/2023.

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