A rare subtype of acute myeloid leukemia characterized by clonal proliferation of poorly differentiated myeloid blasts in the bone marrow, blood or other tissues. It usually presents with anemia, thrombocytopenia and other nonspecific symptoms related to ineffective hematopoesis (fatigue, bleeding and bruising, recurrent infections, bone pain) and/or extramedullary site involvement (gingivitis, splenomegaly). Low remission rates are reported.

An abnormal reduction in numbers of all blood cell types (red blood cells, white blood cells, and platelets).