What is Malignant Mesothelioma?

Medically Reviewed by Carmelita Swiner, MD on November 18, 2020

Malignant mesothelioma is a cancer that most often forms in the thin layers of tissue that line your lungs, chest, or abdomen. In rare cases, it starts in the membranes that surround the heart or testicles.

There are several types of this disease. Doctors know which type you have based on where the cells are located and how they’re arranged.

What Causes It?

You’re more likely to develop malignant mesothelioma if you or someone you live with has been exposed to asbestos (in the workplace, for example) over a long period of time. This mineral fiber is found in rock and soil. It was once used in a number of products, like construction materials, auto parts, and heat-resistant fabrics.

The use of asbestos these days is limited, by law. But it’s still used in some industries. And it can be found in older buildings, including homes. Almost everyone comes into contact with it at some point. You might live or work in an area where you breathed in the substance or swallowed it. Or maybe you or someone in your home worked in construction, auto repair, or shipbuilding.

You can’t see asbestos fibers. They’re too small. But they can get stuck in your clothing or shoes, or cling to your body.

Doctors believe these tiny, needle-like fibers can get inside your body’s tissues. This causes irritation that can lead to the development of cancer cells.

What Are the Symptoms?

You may not have any for 20 to 30 years. If you have pleura mesothelioma (the cancer is in the lining of your lungs) or abdominal mesothelioma, you may experience any of the following:

  • Shortness of breath (caused by fluid buildup around your lungs)
  • Dull chest ache or pain under your rib cage
  • Lumps in your abdomen
  • Unexplained weight loss
  • (In men) a mass in your scrotum

How Do I Know If I Have It?

Your doctor will do a detailed patient history. They may also run a number of tests, including a chest X-ray, biopsy, CT or PET scan, biopsy, and blood tests.

If you have malignant mesothelioma, your doctor will test to see whether the cancer has spread to other parts of your body, such as other tissues or the lymph system.

How Is It Treated?

The stage of the cancer, the size of the tumor, your age, and your heart health, among other things, will figure in to your treatment.

Standard options are surgery, chemotherapy (“chemo”), and radiation therapy. Your doctor might also recommend a combination of surgery and chemo or radiation.

If your cancer is found early, you may find long-term benefit from surgery. That’s because your surgeon is more likely to remove most or all of the cancerous cells. Many times in advanced cases, surgery is not helpful.

For malignant mesothelioma in the chest (the most common form of this cancer), here are some of the surgical options:

  • Wide Local Excision (WLE). Surgeons remove the cancer and some of the healthy tissue around it.
  • Pleurectomy and Decortication. Doctors remove some of the covering of the lungs. They’ll also take out part of the lining of the chest and some of the outside covering of the lungs.
  • Extrapleural Pneumonectomy. Your surgeon will take away one of your lungs. They’ll also remove part of the lining of your chest, your diaphragm, and the lining of the sac around your heart.
  • Pleurodesis. Your doctor will use a catheter to drain fluid that has built up in the space between your chest wall and lungs. Then, chemicals placed into this space will make a scar to help prevent fluid from building up again.

Other Options

These treatments are in clinical trials, where researchers can study their effects on a group of volunteers to see if they work and are safe:

  • Immunotherapy uses your body’s immune system to fight the cancer. One drug being tested makes your immune system block a substance the cancer needs to grow.
  • Targeted therapy attacks certain cancer cells. For example, one therapy takes antibodies made in a lab and uses them to kill the cells, or to keep them from growing or spreading.

Show Sources


NIH, National Cancer Institute: “Malignant Mesothelioma -- Patient Version.”

Cleveland Clinic: “Pleural Mesothelioma.”

EPA: “Learn About Asbestos.”

European Society for Medical Oncology: “Malignant Pleural Mesothelioma: ESMO Clinical Practice Guidelines.”

MD Anderson Cancer Center: “Mesothelioma Treatment.”

Memorial Sloan Kettering Cancer Center: “A Phase I Study Assessing the Immunomodulatory Activity of LY2157299 in Patients with Advanced Solid Tumors.”

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