What is leukemia?

Leukemia is cancer of the blood cells. Normally, the blood produces new cells as needed and as others die off. With leukemia, however, new and functionless cells form and replicate at an uncontrollable rate, overloading the body. Although it begins in the bone marrow, leukemia quickly spreads to the blood and eventually to the lymph nodes, spleen, brain, spinal cord, spinal fluid, and other organs. What sets leukemia apart is that most other forms of cancers start in bodily organs and spread to, not from, the bone marrow.

What are the different types of leukemia?

The four major types of leukemia are:

• acute myeloid leukemia
• acute lymphocytic leukemia
• chronic myeloid leukemia
• chronic lymphocytic leukemia

All leukemias are classified as either acute or chronic. Because blood cells can no longer carry out their tasks, acute leukemia worsens quickly. Conversely, people with chronic leukemia may experience relatively few symptoms early on in the disease, but the disease progresses more rapidly as the number of leukemia cells increases.

What is acute myeloid leukemia?

Acute myeloid leukemia is marked by the uncontrolled growth of dysfunctional cells in the bone marrow and the deficiency of red blood cells, platelets, and white blood cells-the latter of which is caused by the ceased production of normal bone marrow cells. The decrease in healthy red blood cells often causes anemia, while the drop in functional white blood cells and platelets impairs the body's ability to fight infection. Acute myeloid leukemia affects both children and adults.

What is chronic myeloid leukemia?

Chronic myeloid leukemia is very similar to acute myeloid leukemia, except that it does not typically affect children and it develops at a much slower rate. The disease is caused by the presence of too many underdeveloped white blood cells (called lymphoblasts) in the blood or bone marrow.

What is acute lymphocytic leukemia?

Acute lymphocytic leukemia is a rapidly progressing disease that is marked by the overabundance of immature or functionless white blood cells (called lymphoblasts) in the blood and bone marrow. Although it is also found in adults, this is the most common type of leukemia to strike children.

What is chronic lymphocytic leukemia?

Chronic lymphocytic leukemia is caused by the overbundance of mature white blood cells (lymphocytes) in the body. The disease, which begins in the bone marrow but quickly spreads to other organs, rarely affects children and instead typically strikes adults over age 55.

What is lymphoma?

Cancers that originate in the lymphatic system (also called the body's immune system) are called lymphomas. In part, the lymphatic system is composed of lymph nodes, which are small, spherical clusters of lymphocytes, or white blood cells. In a healthy immune system, lymphocytes have a normal cycle of life-they are produced regularly, and they die off regularly. In cases of lymphoma, the lymphatic system becomes abnormal, producing functionless or defective cells at an alarming rate. Lymphomas are classified as either Hodgkin's or Non-Hodgkin's, and both affect adults and children equally. Prognosis and treatment are dependent upon the type of cancer and at which stage it is caught.

What are the different types of lymphoma?

The two types of lymphoma are Hodgkin's lymphoma (Hodgkin's disease) and non-Hodgkin's lymphoma.

What is Hodgkins lymphoma?

An extremely rare form of cancer, Hodgkin's lymphoma accounts for just 1 percent of all cancer cases in the United States. It is triggered by the random, uncontrollable growth of cells in the lymphatic system. These cells amass, forming unhealthy tumors. Because lymphatic tissue can be found throughout the body, Hodgkin's disease can originate anywhere. It usually begins in one lymph node or a group of lymph nodes and then spreads throughout the body, but its causes are not known.

What is non-Hodgkins lymphoma?

Non-Hodgkins lymphoma is cancer of the lymphatic system, the body's immune system. In the immune systems of people with non-Hodgkins lymphoma, abnormal lymphocytes emerge and divide uncontrollably and at an alarming rate, overcrowding the lymph nodes and impairing their functions. This type of cancer accounts for about 5 percent of all cancer cases in the United States and can spread to anywhere in the body, including the bone marrow, liver, spleen, or other organs.

What is aplastic anemia?

Aplastic anemia is a very serious and rare condition in which the bone marrow stops producing enough red and white blood cells to keep the body healthy, resulting in an increased risk of infection and uncontrollable bleeding. The disease can develop in patients of any age and is treatable by medication, bone marrow transplants, and blood transfusions. Another form of the disease, called secondary aplastic anemia, may develop when bone marrow is injured by chemotherapy, cancer, toxic exposure, or in some cases, pregnancy.

What is myelodysplastic syndrome?

Myelodysplastic syndrome is a disease in which the bone marrow produces new blood cells, but those cells are dysfunctional and insufficiently developed. Several or all types of cells are affected in cases of myelodysplastic syndrome, whereas only one type is affected in instances of leukemia. It is important to note that while myelodysplastic syndromes are not cancer, in rare cases, they may lead to it. Treatment options include platelet or red blood cell transfusions, bone marrow transplants, and various medications.

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• Myelodysplastic Syndromes
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