AML is a blood cancer of the myeloid cells in the bone marrow.

The basic stem cells in the bone marrow develop into myeloid cells and lymphoid cells.

Myeloid cells then transform into white blood cells (other than lymphocytes), red blood cells or platelets.

In most types of AML, the myeloid cells that become white blood cells remain immature and multiply uncontrollably. They are called leukaemia cells.

In people with AML who have too many leukaemia cells, the bone marrow becomes congested (Figure 1). It is then unable to produce healthy blood cells. The leukaemia cells are indicated by the red arrows in Figure 1.

Figure 1         Bone marrow in AML with numerous leukaemia cells

By VashiDonsk at the English-language Wikipedia, CC BY-SA 3.0,

AML is the most common leukaemia in the United Kingdom (UK) affecting more than 3000 people/year (Table 1).

Table 1           Main leukaemia and their incidences in the UK (2016-2018)1

Leukaemia type in adults Incidence per 100,000 people No of UK patients affected per year
Acute lymphoblastic leukaemia (ALL) 1.1 791
Acute myeloid leukaemia (AML) 4.9 3089
Chronic lymphocytic leukaemia (CLL) 6.2 3803
Chronic myeloid leukaemia (CML) 1.3 829


  • AML accounts for 80% of acute leukaemia in adults and only 15% to 20% in children. In this course, we are focusing on AML in adults.
  • In the UK, the incidence of AML is different depending on the patient’s age as follows:
  • 0 per 100,000 persons per year in their 20s
  • 0 per 100,000 persons per year in their 80s
  • In adults with AML, the average age at diagnosis is 68 years. AML is slightly more common in males, with a male-to-female ratio of 1.2.