monocytic leukemia symptomsmonoblastic leukemia symptomsacute leukemia treatment optionsacute myeloid leukemiaacute myeloblastic leukemiaacute lymphocyctic leukemiaacute myelogenous leukemiaacute leukemia prognosisacute leukemia diagnosisdefine acute leukemiaacute leukemia in the elderlyacute lymphocytic leukemia prognosis