Hematologic Malignancies

Hematologic malignancies are cancers of the blood, lymph nodes and bone marrow, all of which are closely connected to the immune system. As a result, cancer affecting one of these areas may also affect the other two. Hematologic malignancies affect the production and function of blood cells.

Types of Hematologic Malignancies

Hematologic malignancies are usually divided into three categories, although there are different cancer subsets within each.

Lymphoma

Lymphoma is cancer of the lymphatic system, which is part of the immune system. The lymphatic system is a network of nodes connected by vessels that drain fluid and waste products from all organs and structures in the body. The lymphatic system also produces lymphocytes, white blood cells that help protect against infection and disease. When lymphocytes begin to multiply uncontrollably and produce cancerous cells that invade the body, lymphoma is the result.

Lymphoma can start almost anywhere in the body, and can spread beyond the lymphatic system to other tissues and organs. As abnormal lymphocytes crowd out normal ones, the body's ability to fight disease and infection is compromised. The number of red blood cells can also be affected by the proliferation of abnormal lymphocytes, possibly resulting in anemia. Lymphoma is responsible for approximately 5 percent of all cancers in the United States. Although there are suspected risk factors, lymphoma's cause is unknown.

The two main types of lymphoma are Hodgkin lymphoma, once referred to as Hodgkin disease, and non-Hodgkin lymphoma. Although Hodgkin lymphoma is better known, non-Hodgkin lymphoma is approximately eight times more common.

Myeloma

Myeloma is a cancer that originates in the bone marrow and affects plasma cells. When plasma cells begin to multiply abnormally within the bone marrow, unhealthy levels of protein are released into the bones and blood. As the protein accumulates, it causes organ damage.

Problems are also created inside bones when the plasma cells multiply and crowd out normal bone-marrow blood cells. The myeloma plasma cells release chemicals that trigger the body to dissolve areas of bone. As the disease progresses, plasma cells spill out of the bone marrow and wind up elsewhere in the body, damaging other organs. Myeloma that affects multiple sites is referred to as "multiple myeloma."

Leukemia

Leukemia is a type of cancer that affects the bone marrow and its production of leukocytes (white blood cells). White blood cells normally help fight off infection, but when a patient has leukemia, the bone marrow starts to produce abnormal white blood cells. Called leukemia cells, they do not function the way normal white blood cells should in assisting the body's immune system.

In addition, leukemia cells grow more quickly than normal leukocytes, and do not stop growing when they should. As leukemia progresses, leukemia cells displace normal white blood cells, which can result in various symptoms that include anemia, infections and excessive bleeding. Leukemia cells are also capable of spreading throughout the body to lymph nodes or organs, causing swelling and pain.

In the United States, and as a group, hematological malignancies account for approximately 9.5 percent of new cancer diagnoses each year. Successful treatment is possible, but varies depending on the specific subcategory of blood cancer, the cancer's stage and the patient's overall health.

Additional Resources

• MedlinePlus
• National Institutes of Health
• Centers for Disease Control and Prevention
• Eunice Kennedy Shriver National Institute of Child Health and Human Development
• U.S. Department of Health & Human Services
• U.S. National Library of Medicine
• WebMD

Content presented on this website is for general information only. The healthcare provider | Charles Tilley NP | is not responsible for any content selection, or any errors, inconsistencies, or outdated information.