What is acute myeloid leukemia?

Last medical review:

Acute myeloid leukemia (AML) is a cancer that starts in stem cells of the blood. Stem cells are basic cells that develop into different types of cells that have different jobs. As the stem cells of the blood develop, they become blast cells (blasts), which are immature blood cells. In leukemia, there is an overproduction of blast cells. These blast cells develop abnormally and don't develop into mature blood cells. Over time, the blast cells crowd out normal blood cells so that they can't do their jobs. When leukemia is diagnosed, these blast cells may be called leukemia cells.

There are many different types of leukemia. They are grouped based on the type of blood stem cell they developed from. Blood stem cells develop into either myeloid stem cells or lymphoid stem cells.

Myeloid leukemias develop from abnormal myeloid stem cells. Myeloid stem cells normally develop into different types of mature blood cells – red blood cells, platelets, granulocytes and monocytes.

The types of leukemia are further grouped based on how quickly the leukemia develops and grows. Acute leukemias start suddenly, developing within days or weeks. Chronic leukemias usually develop slowly over months or years.

AML starts in abnormal myeloid stem cells and develops quickly. AML is the most common type of leukemia in adults. It is less common in children.

Diagram of development of blood cells
Diagram of development of blood cells

Expert review and references

  • John Storring, MD, CM
  • Robert Turner, MD, FRCPC
  • Leukemia and Lymphoma Society. The AML Guide: Information for Patients and Caregivers. Rye Brook, NY: 2019: https://www.lls.org/.
  • American Cancer Society. Acute Myeloid Leukemia Early Detection, Diagnosis, and Types . 2018: https://www.cancer.org/.
  • PDQ® Adult Treatment Editorial Board. Acute Myeloid Leukemia Treatment (PDQ®) – Patient Version. Bethesda, MD: National Cancer Institute; 2021: https://www.cancer.gov/.
  • Seiter K. Medscape Reference: Acute Myeloid Leukemia (AML) . WebMD LLC; 2021: https://www.medscape.com/.
  • American Society of Clinical Oncology (ASCO) . Cancer.net: Leukemia – Acute Myeloid . 2017 : https://www.cancer.net/.
  • National Comprehensive Cancer Network. NCCN Guidelines for Patients: Acute Myeloid Leukemia. 2020.

The blood and bone marrow

Bone marrow is the soft, spongy area inside most bones. Its main function is to produce blood cells.