The type of mesothelioma means the type of cell the cancer started in. Knowing this helps your doctor decide which treatment you need.

Where you can get mesothelioma

There are 2 main types of mesothelioma. These are mesothelioma in the:

• covering of the lung (pleural mesothelioma)
• lining of the tummy (peritoneal mesothelioma)

​Pleural mesothelioma starts in the sheets of tissue that cover the lungs. These are called the pleura.

Peritoneal mesothelioma grows in the tissue lining the inside of the tummy (abdomen). This is called the peritoneum.

Pleural mesothelioma is much more common than peritoneal mesothelioma.

Mesothelioma by cell type

Mesothelioma is also grouped according to how the cells look under a microscope. These are the different types:

• epithelioid – the most common type
• biphasic
• sacromatoid
• desmoplastic

Grades

The grade of a cancer tells you how much the cancer cells look like normal cells.

The grade gives your doctor an idea of how the cancer might behave and what treatment you need.

The grades of cancer cells are from 1 to 3:

• grade 1 (low grade) look most like normal cells
• grade 2 look a bit like normal cells
• grade 3 (high grade) look very abnormal and not like normal cells