Types and grades of mesothelioma

Knowing what type of mesothelioma you have helps your doctor decide which treatment you need. The type you have is decided by which cell the cancer started in. 

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.

Rarely, you can also get mesothelioma in other places such as the lining of the heart (pericardium) but we don’t cover these here.

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
  • sarcomatoid
  • 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 mesothelioma cancer cells are from 1 to 4:

  • 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
  • grade 4 cells look the most abnormal
Last reviewed: 
26 Aug 2021
Next review due: 
26 Aug 2024
  • Cancer: Principles and Practice of Oncology (11th edition)
    VT De Vita, TS Lawrence and SA Rosenberg
    Lippincott, Williams and Wilkins, 2019

  • AJCC Cancer staging manual, 8th edition
    MB Amin and others
    Springer, 2017

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