The stages of malignant mesothelioma have been documented by a few different methods.  The most modern of them all is the Brigham System. This system divides malignant mesothelioma into four separate stages, like the other systems.

Stage one — The cancerous tumor is still able to be resected, and lymph nodes haven’t been affected yet.

Stage two — The tumor is still able to be resected, but lymph nodes have started to be affected.

Stage three — The tumor is no longer able to be resected.  The malignant mesothelioma has began to enter the chest wall, heart, diaphragm or abdominal area. Lymph nodes might or might not have been affected yet.

Stage four — The tumor is no longer able to be resected, and has spread completely throughout the body, or metastasized.