Types of Blood Cancer
There are many different types of blood cancer. Blood cancers are named for the type of cell they originate from, as well as whether the cancer cells start in the bone marrow or the lymph nodes. Blood cancers are further categorized by their characteristics, such as if they are fast growing (acute) or slow-growing (chronic). Leukemia is a blood cancer that typically affects the white blood cells, either lymphoid or myeloid. Lymphoma is a blood cancer that begins in the lymphatic system and can be further categorized as Hodgkin or non-Hodgkin lymphoma. Myeloma is a type of cancer that starts in the plasma cells. Myelodysplastic syndromes (MDS) are cancers that develop when immature cells in the bone marrow do not properly mature to become healthy blood cells. Myeloproliferative neoplasms (MPN) are cancers in which blood cells (platelets, WBC, and red blood cells) grow abnormally in the bone marrow.1
What is leukemia?
Leukemia is a cancer in which the white blood cells (WBCs) abnormally multiply in the bone marrow and blood. The large number of irregular WBCs do not fight infection properly, and they can disrupt the formation of red blood cells and platelets.1,2
Leukemias are named for the type of white blood cell that they develop from. Lymphocytic leukemias develop from the immature lymphoid cells, which can become B cells, T cells, and natural killer cells. Myeloid leukemias (also called myelogenous leukemias or myelocytic leukemias) develop from immature myeloid cells, which can become white blood cells, red blood cells, and platelets.1,2
Leukemias are also classified as acute or chronic. Acute leukemias are fast-growing and can progress quickly if not treated, however, they generally respond well to treatment. Chronic leukemias are slower growing, but they can sometimes be harder to treat.1,2
The four major types of leukemia are:
- Acute lymphocytic leukemia (ALL)
- Chronic lymphocytic leukemia (CLL)
- Acute myeloid leukemia (AML)
- Chronic myeloid leukemia (CML)1,2
What is lymphoma?
Lymphoma is a cancer that is found in the lymphatic system, which is comprised of the lymph nodes, lymphatic vessels, and several organs. Lymphomas develop from lymphocytes, WBCs that are important in the immune system. There are two major types of lymphoma: Hodgkin lymphoma (also called Hodgkin disease) and non-Hodgkin lymphoma.2
Lymphocytes, the WBC that can become lymphoma, can normally become B cells or T cells. Similarly, lymphomas may be further classified as B cell lymphoma or T cell lymphoma. Some tend to be slow growing (called low-grade or indolent), and others tend to be fast growing (called high-grade or aggressive).2
What is myeloma?
Myeloma is a cancer that develops from plasma cells, which are B cells (a type of WBC) that have been activated to make a specific antibody. When the plasma cells become cancerous and turn into myeloma, they disrupt the body's ability to produce normal antibodies, which can increase a person's risk of infection. In addition, myeloma can cause kidney damage, and myeloma cells can produce substances that can also damage bone tissue.2
Myeloma is frequently called multiple myeloma because the cancer is usually found in multiple areas of the bone. A single area of myeloma is called a plasmacytoma.1,3
What is myelodysplastic syndromes?
Myelodysplastic syndromes (MDS) are certain types of cancer in which the immature cells in the bone marrow do not properly mature to become healthy blood cells. Some MDS may evolve into a certain type of leukemia, acute myeloid leukemia (AML).5 "Myelo" refers to the myeloid cells, and "dysplastic" refers to abnormal growth or development.
What are myeloproliferative neoplasms?
Myeloproliferative neoplasms (MPN) are cancers in which blood cells (platelets, WBC, and red blood cells) grow abnormally in the bone marrow. "Myelo" refers to the myeloid cells, which are the blood cells that can become red blood cells (RBCs), certain types of WBCs, or platelets. "Proliferative" means to grow or multiply.4,5 MPN can progress to become acute leukemia.
The three classic types of myeloproliferative neoplasms (MPN) include:
- Polycythemia vera, which is characterized by too many RBCs
- Myelofibrosis, which occurs when the bone marrow produces too much collagen or fibrous tissue
- Essential thrombocythemia, which is characterized by too many platelets4