A CBC test can find leukemic blood cells, which are called blasts. It can also detect changes in the amount of any type of blood cell. Finding any one of these changes in the blood can suggest the presence of leukemia.

Are blasts in blood normal?

The number of immature cells (blasts) in the bone marrow is usually normal (less than 5%). A small percentage of the red blood cells in the bone marrow (less than 15%) may contain sideroblasts (iron granules that form a ring).

Do blast cells always mean leukemia?

The most immature cells are called myeloblasts (or blasts). The percentage of blasts in the bone marrow or blood is particularly important. Having at least 20% blasts in the marrow or blood is generally required for a diagnosis of AML.