Cancer starts when cells in a part of the body begin to grow out of control. There are many kinds of cancer. Cells in nearly any part of the body can become cancer. To learn more about cancer and how it starts and grows, see What Is Cancer?
Leukemias are cancers that start in cells that would normally develop into different types of blood cells. Most often, leukemia starts in early forms of white blood cells, but some leukemias start in other blood cell types. There are several types of leukemia, which are divided based mainly on whether the leukemia is acute (fast growing) or chronic (slower growing), and whether it starts in myeloid cells or lymphoid cells.
Acute myeloid leukemia (AML) starts in the bone marrow (the soft inner part of certain bones, where new blood cells are made), but most often it quickly moves into the blood, as well. It can sometimes spread to other parts of the body including the lymph nodes, liver, spleen, central nervous system (brain and spinal cord), and testicles.
Most often, AML develops from cells that would turn into white blood cells (other than lymphocytes), but sometimes AML develops in other types of blood-forming cells. The different types of AML are discussed in Acute Myeloid Leukemia (AML) Subtypes and Prognostic Factors.
Acute myeloid leukemia (AML) has many other names, including acute myelocytic leukemia, acute myelogenous leukemia, acute granulocytic leukemia, and acute non-lymphocytic leukemia.
To understand leukemia, it helps to know about the blood and lymph systems.
Bone marrow is the soft inner part of certain bones. It is made up of blood-forming cells, fat cells, and supporting tissues. A small fraction of the blood-forming cells are blood stem cells.
Inside the bone marrow, blood stem cells develop into new blood cells. During this process, the cells become either lymphocytes (a kind of white blood cell) or other blood-forming cells, which are types of myeloid cells. Myeloid cells can develop into red blood cells, white blood cells (other than lymphocytes), or platelets. These myeloid cells are the ones that are abnormal in AML.
There are 3 main types of blood cells:
There are different types of WBCs:
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Kolitz JE. Overview of acute myeloid leukemia in adults. UpToDate. 2018. Accessed at www.uptodate.com/contents/overview-of-acute-myeloid-leukemia-in-adults on June 12, 2018.
National Cancer Institute. Physician Data Query (PDQ). Adult Acute Myeloid Leukemia Treatment. 2018. Accessed at www.cancer.gov/types/leukemia/hp/adult-aml-treatment-pdq on June 12, 2018.
Raffel GD, Cerny J. Chapter 106: Molecular Biology of Acute Leukemias. In: DeVita VT, Lawrence TS, Rosenberg SA, eds. DeVita, Hellman, and Rosenberg’s Cancer: Principles and Practice of Oncology. 10th ed. Philadelphia, Pa: Lippincott Williams & Wilkins; 2015.
Last Revised: August 21, 2018
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