Rare Acute Leukemias

Hematopoietic cancers, which arise from various cell types that constitute the blood-forming tissues including the cells of the immune system, belong to the group of nonepithelial tumors. The term leukemia (literally “white blood”) refers to malignant derivatives of several of these hematopoietic cell lineages. Acute myeloid leukemia (AML) is a clonal disorder of immature hematopoietic cells and is characterized by aberrant hematopoietic cellular proliferation and maturation. Leukemic blasts might express capabilities for maturation to a variable degree, which leads to morphological heterogeneity. The leukemic transformation might occur at the level of a pluripotent or a less primitive hematopoietic cell. Generally, the transformed leukemic stem cell is committed to the granulocytic lineage, but sometimes a predominance of blast cells from the erythroid or megakaryocytic lineage might be observed.