Leukemia

What is Leukemia? Leukemia is a cancer that starts in the organs that make blood, namely the bone marrow (the soft inner part of the bone) and the lymph system. In leukemia, abnormal and immature white blood cells are produced in the bone marrow and lymph system. The immature white blood cells are called leukocytes.

In some individuals, leukocytes are so numerous that the blood actually has a whitish tinge. When abnormal and immature white blood cells are produced, production of normal cells decreases and the ability to fight infection decreases.

The ability to fight infection decreases because the leukemic cells accumulate and lessen the production of oxygen-carrying red blood cells, blood-clotting cells (platelets), and normal leukocytes. If left untreated, the surplus leukemic cells overwhelm the bone marrow, enter the bloodstream, and will eventually invade other parts of the body, such as the lymph nodes, spleen, liver, and the brain, and spinal cord.

Leukemia means "white blood" in Greek. It occurs when there is an excess of abnormal white blood cells in the blood.

There are 4 major kinds of leukemia: acute, chronic, lymphocytic, and myelogenous. Acute leukemias progress very rapidly, and chronic leukemias progress slowly. The majority of the childhood leukemias are acute leukemias.

Symptoms: There are many symptoms of leukemia and everyone will not experience the same symptoms. Some of the symptoms are: Weakness or chronic fatigue, Fever of unknown origin, Weight loss that is not due to dieting or exercise, Frequent bacterial or viral infections, Headaches, Skin rash, Non-specific bone pain, Easy bruising, Bleeding from gums or nose, Blood in urine or stools, Enlarged lymph nodes and/or spleen, and Abdominal fullness. Doctors can determine the presense of leukemia through blood tests and examinations of bone marrow.

Causes? The cause of most leukemias is unknown. However, researchers are working hard to determine the cause. Researchers do know that leukemia occurs in males more often than in females and in white people more often than in black people. However, researchers cannot explain why one person gets leukemia and another does not.

Types of leukemia? : There are several types of leukemia. They are grouped in two ways. One way is by how quickly the disease develops and gets worse. The other way is by the type of blood cell that is affected.

Leukemia is either acute or chronic, lymphocytic or myelogenous. In acute leukemia, the abnormal blood cells are blasts that remain very immature and cannot carry out their normal functions. The number of blasts increases rapidly, and the disease becomes worse quickly. There are different kinds of acute leukemias:

In chronic leukemia, some blast cells are present, but in general, these cells are more mature and can carry out some of their normal functions. refers to a condition where the cells look mature but they are not completely normal. The cells live too long and cause a build-up of certain kinds of white blood cells. Also, the number of blasts increases less rapidly than in acute leukemia. As a result, chronic leukemia worsens gradually.

Lymphocytic and myelogenous (or myeloid) leukemia refer to the two different kinds of cells from which leukemias start. Lymphocytic leukemias develop from lymphocytes in the bone marrow. Myelogenous leukemia (also called myelocytic) develops from either granulocyte white blood cells or monocyte white blood cells.

Acute lymphocytic leukemia (ALL)
* Affects children and adults
* More common among children
* Accounts for slightly more than half of all cases of childhood leukemia

Chronic lymphocytic leukemia (CLL)
* Affects adults
* Almost twice as common as CML

Acute myelogenous leukemia (AML)
(also called Acute nonlymphocytic leukemia: ANLL)
* Affects children and adults
* Accounts for just under half of cases of childhood leukemia

Chronic myelogenous leukemia (CML)
* Affects mostly adults: very rare in children
* About half as common as CLL