<unk>  (Greek leukos, “white”; haima, “blood”) can be defined as a group of hematopoietic stem cell malignancies due to genetic abnormalities that may lead to clonal proliferation of these cells. These group of diseases are classified based on the type of hematopoietic stem cell involved and the duration of the disease. The<unk> s are the most common malignancies among children younger than 15 years. Among them, Acute Lymphoblastic<unk>  (ALL) is the most common<unk>  and accounts for 77% of childhood<unk> . However, Chronic Lymphocytic<unk>  (CLL) is the most common form of<unk>  in adults, and it accounts for 30% of all<unk> s in the United States. The increased rate of proliferation and decreased rate of apoptosis in this progeny of cells may compromise normal bone marrow function and ultimately result in marrow failure. Clinical manifestations, diagnosis, laboratory findings, and therapy are different according to the type of malignancy.
Leukemia
Agranulocytosis
Granulocytosis
Leukopenia
Myeloid leukemia
Acute myeloid leukemia
Aleukemic leukemia
Myelofibrosis