Doctors use three main staging systems for mesothelioma, especially for the pleural type: Butchart, TNM, and Brigham. The last two are the most frequently used by specialists but some doctors believe that none of them is accurate enough.

Doctors use the Brigham system to examine tissues, organs and other different structures of the body in order to discover how advanced the disease is.

The TNM system is used to stage different types of cancer, not just mesothelioma. The abbreviation represents the most important aspects of the disease:

T: the location and size of the tumor

N: spreading of the tumor to the lymph nodes

M: metastasis of the cancer

The Butchart system uses the same criteria as the Brigham and TNM systems and is the oldest way of staging the pleural form of mesothelioma.