Non-Hodgkin's lymphoma (NHL) is a type of cancer that causes the cells of the lymphatic system to abnormally reproduce and spur the growth of tumors. These tumors may be present in one region of the body, or they may spread to other lymph nodes or organs, the brain or spinal cord. The stages of non-Hodgkin's lymphoma are characterized according to the extent to which the cancer has spread and whether key symptoms of illness are present.
Stage I
Individuals are diagnosed with stage I non-Hodgkin's lymphoma if their disease is either in a lymph node or nodes in one region of the body (for example, the neck, groin or underarm) or if the cancer is found in only one organ outside of the lymph system. According to the Merck Manuals Online Medical Library, only 10 to 30 percent of people with non-Hodgkin's lymphoma have disease limited to one region.
Stage II
Stage II non-Hodgkin's lymphoma is diagnosed if the tumor is at two or more sites on the same side of the body. Specifically, the lymphoma may be in two or more groups of lymph nodes on the same side of the diaphragm (either both above or both below), such as lymph nodes under the arm and in the neck (but not lymph nodes under the arm and in the groin). Alternatively, the lymphoma may extend from one lymph node or group of lymph nodes to a nearby organ or other groups of lymph nodes on the same side of the diaphragm, the American Cancer Society (ACS) reports.
Stage III
Stage III non-Hodgkin's lymphoma is diagnosed when any number of tumors occur on both sides of the body, as long as there is no involvement of bone marrow or the central nervous system. The ACS explains that the lymphoma must be found either in lymph node regions on both sides of the diaphragm or must have spread into nearby organs, lymph nodes and/or the spleen.
Stage IV
Stage IV non-Hodgkin's lymphoma is diagnosed when the cancer has spread to the bone marrow, liver, central nervous system (brain and spinal cord) or lining of the lungs (pleura) or when the lymphoma spreads to a distant organ that is far away from an involved lymph node. According to the Children's Hospital of Boston, stage IV non-Hodgkin's lymphomas are further subdivided depending upon the amount of cancer cells present in the bone marrow.
"A" and "B" Staging
To each of the numeric stages described above, the letter "A" or "B" is added based on assessment of additional disease symptoms, according to the ACS. Patients experiencing significant unexplained weight loss (more than 10 percent loss of body weight), soaking night sweats or an unexplained fever of 101.5 degrees Fahrenheit or above will have the letter "B" added to their stage (for example, stage IIIB). If none of those three symptoms is present, the letter "A" is added to the numeric stage.
