The type of malignant mesothelioma depends on the cell in which it began. The most common type of malignant mesothelioma is epithelial mesothelioma, which forms in the cells that line organs. The other types begin in spindle-shaped cells called sarcomatoid cells or are a mixture of both cell types. Epithelial mesothelioma may grow more slowly and have a better prognosis than other types.

If products containing asbestos are disturbed, tiny asbestos fibers are released into the air. When asbestos fibers are breathed in, they may get trapped in the lungs and remain there for a long time. Over time, accumulated asbestos fibers can cause tissue inflammation and scarring, which can affect breathing and lead to serious health problems.

Immunohistochemistry: A test that uses antibodies to check for certain antigens in a sample of tissue. The antibody is usually linked to a radioactive substance or a dye that causes the tissue to light up under a microscope. This type of test may be used to tell the difference between different types of cancer.