Acquired clonal disorder of hematopoietic stem cells, leading to hypercellular marrow, abnormal cell morphology, and cytopenias
Idiopathic or secondary to chemotherapy or radiation
May evolve into acute myeloid leukemia
Myelodysplastic syndrome
Acute leukemia, infiltrative malignancy 
Acute myeloid leukemia
Myelodysplastic syndrome, myelofibrosis
Leukemoid Reaction
Aplastic anemia
Chronic myeloid leukemia
Paroxysmal nocturnal hemoglobinuria