Acute Myeloid Leukemia (AML)

Acute myeloid leukemia (AML) is a cancer of the myeloid line of blood cells, characterized by the rapid growth of abnormal white blood cells that build up in the bone marrow and interfere with the production of normal blood cells. AML is the most common acute leukemia affecting adults, and its incidence increases with age.


Leukaemia is a type of cancer of the blood. There are different forms of leukaemia depending on the type of blood cell affected. "Acute" describes a rapid progression, and "myeloblastic" denotes the origin from myeloid cells. Myeloid cells are immature cells that normally become mature red blood cells, white blood cells, or platelets. In acute myeloid leukaemia, the bone marrow produces too many early (immature) blood cells which do not go on to become mature blood cells. Platelets play a critical role in stopping bleeding and red blood cells are important in delivering oxygen to all cells in the body. Excess production of immature myleloid blood cells in the bone marrow ultimately prevents the normal production of red blood cells, resulting in anaemia and decreased production of platelets or thrombocytompenia. Patients with AML seek medical care due to lack of energy and fatigue from anaemia or bleeding and bruising from insufficient platelets. Without enough normally functioning white blood cells the body"s immune system also becomes weak and susceptible to infection. Other symptoms include fever, shortness of breath and bone pain. At diagnosis, most patients - though not all - have a white blood cell count (the number of white blood cells circulating in the blood) that is above normal.


The cause of acute myeloblastic leukaemia (AML) is not understood. A small number of predisposing risk factors have been identified due to catastrophic events, including the atomic bombing of Hiroshima and the nuclear reactor accident in Chernobyl. A risk factor increases the chance of cancer occurring, but it in itself does not cause cancer. If you have a risk factor it does not necessarily mean you will develop cancer. A risk factor is not a cause in itself.

Risk factors


Bone marrow aspiration is the diagnostic procedure. The WHO classification requires more than 20% blasts in the peripheral blood, to make a diagnosis of AML. Patients potentially suitable for allogeneic stem cell transplantation (alloSCT) should be HLA typed at diagnosis, as should their available first-degree family members. In high-risk disease (eg, poor karyotype), early matched unrelated donor allogeneic transplantation must be considered, and a donor search should be performed as early as possible. Cytochemical stains allow classification into seven of the subtypes M1 to M7. These stains may not be useful for M0 (acute undifferentiated leukaemia) or M7 (acute megakaryocytic leukaemia) and so flow cytometry is used. Cytogenetic studies are also performed to provide important information about prognosis. They are also useful to confirm acute promyelocytic leukaemia (APL), which shows the t(15;17) and is treated differently. Chromosomal analyses are performed on children with AML to identify subgroups for prognostic assessment and to tailor therapy. Techniques such as gene expression profiling are increasingly used.

Signs and symptoms

Due to the excessive proliferation of myeloid precursor cells in bone marrow, certain symptoms/lab findings are expected (e.g. as a result of pancytopenia)