Leukemia is cancer caused by white blood cells that develop abnormally in bone marrow. In acute myeloid leukemia (AML), myeloblasts, an immature type of white blood cell, multiply uncontrollably. They are unable to develop into mature myelocytes or function properly.
Chronic myelomonocytic leukemia (CMML) is a rare cancer of the white blood cells. It occurs when a mature type of white blood cell, monocytes, do not develop normally. These abnormal cells grow out of control and crowd out healthy blood cells.
Myelodysplastic syndromes (MDS) are a group of conditions defined by the inability of bone marrow to make enough healthy blood cells. People with MDS don't have enough of at least one type of blood cell. In addition, some of their blood cells are abnormally shaped.