Acute Myeloid Leukaemia (AML)
Acute myeloid leukaemia (AML) is a rare type of cancer. AML is also sometimes known as acute non-lymphocytic leukaemia (ANLL). AML is a condition where the bone marrow makes large numbers of abnormal immature white blood cells which are derived from a myeloid stem cell. The abnormal immature cells are called blasts.
There are various sub-types of AML, depending on exactly what cell type becomes cancerous and at what stage in the maturing process. There are eight main sub-types which are called M0, M1, M2, etc., up to M7. These are sometimes called more descriptive names such as 'acute myelomonocytic leukaemia' (AMML) (this is M4 where the blast cell is one which would normally have developed in to a monocyte), and 'acute myeloid leukaemia with minimal evidence of myeloid differentiation' (this is M0 where the blast cell is a very immature cell), etc.
Typically, AML develops quite quickly (acutely) and rapidly becomes worse (over a few weeks or so) unless treated. Around 2,000 adults and about 50 children are diagnosed in the UK each year, most cases occur in people aged over 50. AML is rare in people under the age of 20. It is slightly more common in men than in women. AML can affect people at any age, but is most common in people over 65.
Normally, blood cells are made in the bone marrow in an orderly and controlled way. In AML, this process gets out of control and many abnormal leukaemia cells are made. These immature cells aren’t able to develop into normal functioning blood cells.
AML is an overproduction of an early myeloid cell. In most types of AML the leukaemia cells are immature white cells. But, in some less common types of AML, too many immature platelets or immature red blood cells are made.
The immature cells fill up the bone marrow, taking up space that’s needed to make normal blood cells. Some leukaemia cells ‘spill over’ into the blood and circulate around the body in the bloodstream. These leukaemia cells don’t mature, and so don’t work properly. This leads to an increased risk of infection as well as symptoms such as anaemia and bruising caused by fewer healthy red blood cells and platelets being made.
Reviewed April 2013