Types

Types of Leukemia

Leukemia is cancer of blood-forming tissue such as bone marrow. Types of leukemia are classified by the type of cell affected and by the rate of cell growth. Leukemia may be either classified as acute or chronic.

Acute leukemia involves an overgrowth of very immature blood cells. This condition is life threatening because there are not enough mature blood cells to prevent anemia, infection, and bleeding.

Chronic leukemia involves an overgrowth of very mature blood cells. Usually, people with chronic leukemia have enough mature blood cells to prevent serious bleeding and infection.

Myelodysplastic Syndrome (MDS) is a condition in which the bone marrow does not function normally and therefore does not produce enough normal blood cells. The blood cells affected are white blood cells, red blood cells, and platelets.

Different forms of leukemia tend to be linked with certain age groups. Acute lymphoblastic leukemia is most common during childhood and in early adulthood, although it is also diagnosed in adults 30 years and older. Acute myelogenous leukemia occurs more often in adults. Chronic leukemia is more prevalent between ages 40 and 70 and is rare among young people. MDS is most often found in patients nearing their 60s and 70's. However, there are always exceptions.

Doctors identify a specific type of leukemia on the basis of chromosome number and appearance, features on the bone marrow cell surface, and the appearance of the bone marrow cells under microscope. The following is a list of the different types of leukemia.

Acute Leukemias

Myeloid