Leukemia is a malignant proliferation of white blood cell precursors in bone mar or mph tissue and their accumulation in peripheral blood, bone marrow, and body tissues. The blood's cellular components originate primarily in the marrow of bones such as the sternum, iliac crest, and cranium. All blood cells begin as immature cells (blasts or stem cells) that differentiate and mature into RBCs, platelets, and various types of wBCs. In leukemia, many immature or ineffective WBCs crowd out the developing normal ce As the normal cells are replaced by leukemic cells, anemia, neutropenia, and thrombocytopenia occur