After diagnosis, your doctor will run more tests to find out where the cancer is and if it has spread. PMBCL stages are similar to other lymphomas:
Stage I: The cancer is in one area only.
Stage II: The cancer is in two or more areas on one side of the diaphragm, the large muscle beneath the lungs.
Stage III: The cancer is on both sides of the diaphragm.
Stage IV: The cancer has spread to other organs and tissues. This may include the liver, lung, or bone marrow.