Acute myeloid leukemia (AML) is a blood cancer. It happens when young abnormal white blood cells called blasts (leukemia cells), begin to fill up the bone marrow , preventing normal blood production. Doctors diagnose AML when 20 out of every 100 white blood cells in the bone marrow is a blast cell .

Does AML have blasts?

Having at least 20% blasts in the marrow or blood is generally required for a diagnosis of AML. (In normal bone marrow, the blast count is 5% or less, while the blood usually doesn't contain any blasts.)

What do blasts in the blood mean?

Blasts are precursors to the mature, circulating blood cells such as neutrophils, monocytes, lymphocytes and erythrocytes. Blasts are usually found in low numbers in the bone marrow. They are not usually found in significant numbers in the blood.