acute lymphocyctic leukemiaacute myeloblastic leukemiaacute myelogenous leukemiaacute leukemia diagnosisacute leukemia prognosisdefine acute leukemiaacute leukemia in the elderlyacute monocytic leukemia symptomsacute myeloid leukemiastages of acute leukemiaacute lymphoblastic leukemia prognosisacute myeloid leukemia diagnosis