Leukemia, acute myeloid: A quickly progressive malignancy in which there are too many immature blood-forming cells that are precursors to the granulocytes or monocytes (types of white blood cells) in the blood and bone marrow. Abbreviated AML. AML can occur in children and adults. In AML, the red blood cell levels may be low, causing anemia. Platelet levels may be low, causing bleeding and bruising and the white blood cell levels may be low, leading to infections. Treatments for AML include chemotherapy and bone marrow transplantation. The treatment of the subtype of AML called acute promyelocytic leukemia ((APL) differs from that for other forms of AML, as this is the most malignant form of AML.APL is also known as acute myelogenous leukemia and acute nonlymphocytic leukemia (ANLL).