Mesothelioma Diagnosis

The symptoms of mesothelioma often are the same as those of other diseases. This may make mesothelioma hard to diagnose. In particular, pleural effusion (fluid build-up in the chest cavity) may be found in several other diseases including lung cancer, heart failure and pneumonia. Early and precise diagnosis is important for successful mesothelioma treatment. However, doctors often are unsure if a person has mesothelioma, even after chest fluid has been removed and tested.

Experience counts

Mesothelioma is a rare disease, so it can be difficult to diagnose. Pathologists at MD Anderson have special expertise in diagnosing mesothelioma and its subtypes. Having an accurate diagnosis from the start can help doctors plan the best possible treatment plan.

Mesothelioma diagnosis

If you have symptoms that may signal mesothelioma, your doctor will examine you and ask you questions about your health; your lifestyle, including smoking and drinking habits; and your exposure to asbestos. One or more of the following tests may be used to find out if you have mesothelioma and if it has spread. These tests also may be used to help plan treatments and determine if treatment is working.

Biopsy: Biopsy involves the removal of suspected cancer tissue for study under a microscope. It is typically the only way to definitively diagnose mesothelioma. There are two main types of biopsy used in mesothelioma diagnosis:

Needle biopsy: Doctors insert a needle into the chest and either sample part of the tumor or drain fluid from the area. The fluid can be examined for cancer cells.
Thoracoscopic surgical biopsy: During this procedure, a small incision is made in the chest. A tiny tube with a camera on the end is inserted, and a small amount of tissue is removed for examination.

Imaging exams: Imaging can assist in the diagnosis. Images can help doctors determine the extent of the disease and make treatment plans. Imaging tests for mesothelioma may include:

CT or CAT (computed axial tomography) scans
MRI (magnetic resonance imaging) scans
PET (positron emission tomography) scans
Chest X-ray

Learn more about imaging exams.

Lung function test: Lung function tests are not used to diagnose mesothelioma. Instead, they help determine the condition of the patient’s lungs. Patients whose lungs are working well are more likely to be good candidates for surgery.

In rare cases, mesothelioma can be passed down from one generation to the next. Genetic counseling may be right for you. Visit our genetic testing page to learn more.

Mesothelioma Staging

If you are diagnosed with mesothelioma, your doctor will determine the stage of the disease. Staging is a way of classifying cancer by how much disease is in the body and where it has spread when it is diagnosed. Staging helps the doctor plan the best way to treat the cancer. Surgery often is needed to stage mesothelioma. Once the staging classification is determined, it stays the same even if treatment works or the cancer spreads.

Mesothelioma Stages

(source: National Cancer Institute)

Stage I

Stage I is divided into stages IA and IB:

In stage IA, cancer is found in the inside lining of the chest wall on one side of the chest. On the same side of the chest, cancer may also be found in one or more of the following:
- The thin layer of tissue that covers the lung.
- The thin layer of tissue that covers the organs between the lungs.
- The thin layer of tissue that covers the top of the diaphragm.
In stage IB, cancer is found in the inside lining of the chest wall, and in each of the thin layers of tissue that cover the lung, the organs between the lungs, and the top of the diaphragm on one side of the chest. On the same side of the chest, cancer has also spread into one or more of the following:
- Diaphragm.
- Lung tissue.
- Tissue between the ribs and the inside lining of the chest wall.
- Fat in the area between the lungs.
- Soft tissues of the chest wall.
- Sac around the heart.

Stage II

In stage II, cancer is found in the inside lining of the chest wall on one side of the chest. On the same side of the chest, cancer may also be found in one or more of the following:

The thin layer of tissue that covers the lung.
The thin layer of tissue that covers the organs between the lungs.
The thin layer of tissue that covers the top of the diaphragm.

Cancer has spread to lymph nodes along the center of the chest on the same side of the chest as the tumor.

Cancer is found in the inside lining of the chest wall, and in each of the thin layers of tissue that cover the lung, the organs between the lungs, and the top of the diaphragm on one side of the chest. On the same side of the chest, cancer has also spread into one or both of the following:

Diaphragm.
Lung tissue.

Cancer has spread to lymph nodes along the center of the chest on the same side of the chest as the tumor.

Stage III

Stage III is divided into stages IIIA and IIIB.

In stage IIIA, cancer is found in the inside lining of the chest wall, and in each of the thin layers of tissue that cover the lung, the organs between the lungs, and the top of the diaphragm on one side of the chest. On the same side of the chest, cancer has also spread into one or more of the following:
- Tissue between the ribs and the inside lining of the chest wall.
- Fat in the area between the lungs.
- Soft tissues of the chest wall.
- Sac around the heart.

Cancer has spread to lymph nodes along the center of the chest on the same side of the chest as the tumor.

In stage IIIB, cancer is found in the inside lining of the chest wall, and may also be found in the thin layers of tissue that cover the lung, the organs between the lungs, and/or the top of the diaphragm on one side of the chest. On the same side of the chest, cancer may have also spread into one or more of the following:
- Diaphragm.
- Lung tissue.
- Tissue between the ribs and the inside lining of the chest wall.
- Fat in the area between the lungs.
- Soft tissues of the chest wall.
- Sac around the heart.

Cancer has spread to lymph nodes above the collarbone on either side of the chest or cancer has spread to lymph nodes along the center of the chest on the opposite side of the chest as the tumor.

Cancer is found in the inside lining of the chest wall, and in each of the thin layers of tissue that cover the lung, the organs between the lungs, and the top of the diaphragm on one side of the chest. Cancer has also spread to one or more of the following:
- The chest wall and may be found in the rib.
- Through the diaphragm into the peritoneum.
- The tissue lining the chest on the opposite side of the body as the tumor.
- The organs in the area between the lungs (esophagus, trachea, thymus, blood vessels).
- The spine.
- Through the sac around the heart or into the heart muscle.

Cancer may have spread to lymph nodes.

Stage IV

In stage IV, cancer has spread to the tissue covering the lung or the lung on the opposite side of the chest, peritoneum, bones, liver, lymph nodes outside the chest, or to other parts of the body.

Mesothelioma Diagnosis