Cancer is normally named for the location on the body in which it starts (for example, breast cancer starts in the breast). Non-Hodgkin lymphoma is distinct from other cancers because it does not start in one particular part of the body. It can start anywhere within the lymph cells, which are located wherever there are lymph nodes or lymph tissue. The lymph system and the lymph cells are a part of the immune system, and lymph nodes are found throughout the body, including in bone marrow. While certain other types of cancer may eventually spread to the lymph nodes, this does not make these other cancers qualify as non-Hodgkin lymphoma, since the cancer did not originate in the lymph system.
Types of Non-Hodgkin Lymphoma
According to the American Cancer Society, classification of non-Hodgkin lymphoma is very difficult due to the wide variety of types that exist. The Society states that there are over 30 types of non-Hodgkin lymphoma, and that there are several different classification systems used to identify lymphoma by type. As of July 2009, the standard system for classifying non-Hodgkin lymphoma is the WHO system, pioneered by the World Health Organization. This system classifies lymphoma based upon the appearance and chromosomes of the cells, as well as the presence or absence of chemicals on the cell surface.
B-Cell Lymphomas
The vast majority of non-Hodgkin's lymphomas are B cell lymphomas. According to the American Cancer society, approximately 85 percent of all cases of non-Hodgkin lymphoma are caused by some type of B cell. One particular B cell lymphoma, called Diffuse Large B-cell Lymphoma (DLBCL), is especially prevalent, as one in every three diagnosed non-Hodgkin lymphomas are caused by DLBCL. People of any age group are prone to DLBCL, but it is more common in older people, and the average age of a patient at diagnosis is in the 60s. Symptoms include the presence of a mass in the lymph nodes that is large enough to feel. The lymphoma is often present in only one part of the body, and can often be successfully cured with chemotherapy.
Follicular Lymphoma
Follicular lymphoma is another common classification, and the American Cancer Society suggests that it accounts for one in four non-Hodgkin lymphomas. Again, most patients diagnosed with this illness are in their 60s; it is rare in younger people. Approximately 90 percent of the time, follicular lymphoma is identified in multiple areas in the body and in the bone marrow. There is no cure for follicular lymphoma, but it is a slow-growing cancer, and between 60 and 70 percent of people diagnosed with it are alive five years after diagnosis.
Lymphocytic Lymphoma
Chronic lymphocytic leukemia (CLL) and small lymphocytic lymphoma (SLL) are related types that together account for one in four lymphomas. CLL is often found in the bone marrow and blood, while SLL usually appears in the lymph nodes, but both have the same type of cancer cell. Neither CLL nor SLL is curable, but CLL tends to be slower-growing. Neither CLL nor SLL is a very aggressive lymphoma, and patients can live upwards of 10 years before the disease progresses to a more aggressive lymphoma.
Mantle Cell Lymphoma
Mantle cell lymphoma is responsible for approximately 5 percent of non-Hodgkin lymphomas. Again, it affects older people--those in their 60s--but it primarily affects men. Mantle cell lymphoma is typically found in multiple lymph nodes, and may also be present in the bone marrow or spleen. The survival rate is low, and the American Cancer Society states that only one in five patients with mantle cell lymphoma is alive five years after diagnosis.
Tags: lymph nodes, American Cancer, bone marrow, cell lymphoma, non-Hodgkin lymphoma, non-Hodgkin lymphomas