Key Points for This Section

Atypical chronic myelogenous leukemia is a disease in which too many granulocytes (immature white blood cells) are made in the bone marrow. Possible signs of atypical chronic myelogenous leukemia include easy bruising or bleeding and feeling tired and weak. Certain factors affect prognosis (chance of recovery).

Atypical chronic myelogenous leukemia is a disease in which too many granulocytes (immature white blood cells) are made in the bone marrow.

In atypical chronic myelogenous leukemia (aCML), the body tells too many blood stem cells to develop into a type of white blood cell called granulocytes. Some of these blood stem cells never become mature white blood cells. These immature white blood cells are called blasts. Over time, the granulocytes and blasts crowd out the red blood cells and platelets in the bone marrow.

The leukemia cells in aCML and chronic myelogenous leukemia (CML) look alike under a microscope. However, in aCML a certain chromosome change, called the "Philadelphia chromosome" is not present.

Possible signs of atypical chronic myelogenous leukemia include easy bruising or bleeding and feeling tired and weak.

These and other symptoms may be caused by aCML. Other conditions may cause the same symptoms. A doctor should be consulted if any of the following problems occur:

• Shortness of breath.
• Pale skin.
• Feeling very tired and weak.
• Easy bruising or bleeding.
• Petechiae (flat, pinpoint spots under the skin caused by bleeding).
• Pain or a feeling of fullness below the ribs on the left side.

Certain factors affect prognosis (chance of recovery).

The prognosis (chance of recovery) for aCML depends on the number of red blood cells and platelets in the blood.

Glossary Terms

An immature blood cell.

A tissue with red blood cells, white blood cells, platelets, and other substances suspended in fluid called plasma. Blood takes oxygen and nutrients to the tissues, and carries away wastes.

The soft, sponge-like tissue in the center of most bones. It produces white blood cells, red blood cells, and platelets.

The individual unit that makes up the tissues of the body. All living things are made up of one or more cells.

Part of a cell that contains genetic information. Except for sperm and eggs, all human cells contain 46 chromosomes.

A slowly progressing disease in which too many white blood cells (not lymphocytes) are made in the bone marrow. Also called chronic granulocytic leukemia, chronic myeloid leukemia, and CML.

A type of immune cell that has granules (small particles) with enzymes that are released during infections, allergic reactions, and asthma. Neutrophils, eosinophils, and basophils are granulocytes. A granulocyte is a type of white blood cell. Also called granular leukocyte, PMN, and polymorphonuclear leukocyte.

Cancer that starts in blood-forming tissue such as the bone marrow and causes large numbers of blood cells to be produced and enter the bloodstream.

Pinpoint, unraised, round red spots under the skin caused by bleeding.

An abnormality of chromosome 22 in which part of chromosome 9 is transferred to it. Bone marrow cells that contain the Philadelphia chromosome are often found in chronic myelogenous leukemia.

A tiny piece of a cell found in the blood that breaks off from a large cell found in the bone marrow. Platelets help wounds heal and prevent bleeding by forming blood clots. Also called thrombocyte.

The likely outcome or course of a disease; the chance of recovery or recurrence.

A cell that carries oxygen to all parts of the body. Also called erythrocyte and RBC.

A cell from which other types of cells develop. For example, blood cells develop from blood-forming stem cells.

An indication that a person has a condition or disease. Some examples of symptoms are headache, fever, fatigue, nausea, vomiting, and pain.

A type of immune cell. Most white blood cells are made in the bone marrow and are found in the blood and lymph tissue. White blood cells help the body fight infections and other diseases. Granulocytes, monocytes, and lymphocytes are white blood cells. Also called leukocyte and WBC.