Different Types of Leukemia
Acute Lymphocytic Leukemia (ALL)
Acute lymphocytic leukemia, also called acute lymphoblastic leukemia and acute lymphoid leukemia, is a common leukemia. About 4,000 new cases are diagnosed each year in the United States. Most cases of acute lymphocytic leukemia (ALL) occur in children under age 10, but it can appear in all age groups. ALL is an acute leukemia, which means it is a disease that worsens quickly.
ALL is not inherited. It is caused by a change in the cells in the bone marrow. In most cases the cause is unknown but a few environmental factors are linked with ALL such as high doses of radiation and exposure to toxins before birth or in early childhood.
Chronic Myelogenous Leukemia (CML)
Chronic myelogenous leukemia (CML), also known as chronic myeloid or chronic myelocytic leukemia, is a relatively uncommon leukemia, with about 5,000 new cases diagnosed each year in the United States. Most cases of CML occur in adults, but about 2 percent of all CML cases occur in children. Although, CML is not an inherited, it has a genetic component.
It is caused by a change in a chromosome called the Philadelphia chromosome in bone marrow cells that leads to overproduction of white blood cells. As the "chronic" in its name implies, CML usually develops slowly, although it can progress to a fast-growing "accelerated phase." Although chemotherapy can induce long periods of remission (periods when white blood cell counts and symptoms are reduced), stem cell transplantation is currently the only known cure for CML.
Chronic Lymphocytic Leukemia (CLL)
Chronic lymphocytic leukemia (CLL) is the most common form of adult leukemia, accounting for approximately 7,000 new cases a year in the United States. Men are twice as likely to develop CLL as women. The key risk factor is age: over 75 percent of CLL cases are diagnosed after age sixty.
CLL is a progressive disease for which no cure is available. The cancer produces abnormal white blood cells that are very long-lived. Instead of the rapid accumulation of white blood cells that characterizes acute forms of the disease, CLL cells are thought to slowly accumulate because of a longer life span. Eventually, the leukemic cells crowd out healthy white blood cells, platelets, and red blood cells.
Because the cancer progresses at such a slow rate, and given the lack of a cure, treatment is usually delayed until symptoms develop. Watchful waiting, or the careful monitoring of progression and symptoms, is often recommended.
Hairy Cell Leukemia (HCL)
Hairy cell leukemia (HCL) is an uncommon cancer of the blood. It can be one of the causes of low numbers of normal blood cells. The disease is caused by the abnormal growth of B cells that can look "hairy" under the microscope because they have fine projections coming from their surface.
The cause of this disease is unknown. It affects men 5 times more often than women, and the average age of onset is 55. Hairy cell leukemia is rare and only accounts for about 2% of the leukemias diagnosed each year.
|