Leukemia (leucemia) is a group of bone marrow and blood disease. They are malignant disease (
cancer) characterized by an uncontrolled increase in white blood cells (leukocytes).
There are 4 major forms of leukemia: myelogenous and lymphocytic leukemia each have acute and chronic forms. The terms myelogenous or lymphocytic refer to the cell type involved.
Chronic myelogenous leukemia (CML, Chronic granulocytic leukemia; Leukemia - Chronic granulocytic) is a malignant cancer of the bone marrow. It causes rapid growth of the blood-forming cells (known as myeloid precursors) in the bone marrow, peripheral blood, and body tissues. The disease accounts for 7% to 20% cases of leukemia (estimated 2740 ~ 6960 new cases in USA in 2005). It is usually associated with a chromosome abnormality called the Philadelphia chromosome.
Chronic lymphocytic leukemia (CLL) is a malignancy (cancer) of the white blood cells (lymphocytes) characterized by a slow, progressive increase of these cells in the blood and the bone marrow. It's the second most common leukemia in adults, estimated about 28% of leukemia new cases in USA in 2005. In general, the incidence is about 2 per 100,000 and increases with age (90% of cases are found in people over 50). Chronic lymphocytic leukemia (CLL) affects the B lymphocytes and causes immunosuppression, failure of the bone marrow, and invasion of malignant (cancerous) cells into organs
Hairy cell leukemia (Leukemic reticuloendotheliosis; HCL; Leukemia - hairy cell ) is a type of chronic lymphocytic leukemia (CLL). It's so called because the leukemic lymphocytes have short, thin projections from their surface that look like hairs when examined under a microscope.
Acute myelogenous leukemia (AML; Acute myeloid leukemia (AML); Acute granulocytic leukemia; Acute nonlymphocytic leukemia (ANLL); Leukemia - acute myeloid (AML); Leukemia - acute granulocytic; Leukemia - nonlymphocyctic (ANLL)) is a cancer of blood-forming tissues of the bone marrow characterized by the growth of immature white blood cells. This is the most common types of leukemia in adults, estimated about 11,960 (~34% of all leukemia) new cases in USA 2005.
Acute lymphocytic leukemia (ALL; Acute childhood leukemia; Cancer - acute childhood leukemia (ALL); Leukemia - acute childhood (ALL) ) is a progressive, malignant disease characterized by large numbers of immature white blood cells that resemble lymphoblasts. Acute lymphocytic leukemia (ALL) is responsible for 80% of the acute leukemias of childhood, with the peak incidence occurring between ages 3 and 7. It's estimated about 3910 new cases in USA 2005.
