Blood cell development. A blood stem cell goes through several steps to become a red blood cell, platelet, or white blood cell.
In ALL, too many stem cells develop into lymphoblasts or lymphocytes. These cells may also be called leukemic cells. These leukemic cells are not able to fight infection very well. Also, as the number of leukemic cells increases in the blood and bone marrow, there is less room for healthy white blood cells, red blood cells, and platelets. This may cause infection, anemia, and easy bleeding. The cancer can also spread to the central nervous system (brain and spinal
This summary is about adult acute lymphoblastic leukemia.
See the following PDQ summaries for information on other types of leukemia:
Previous chemotherapy and exposure to radiation may increase the risk of developing ALL.
Anything that increases your risk of getting a disease is called a risk factor. Having a risk factor does not mean that you will get cancer; not having risk factors doesn’t mean that you will not get cancer. People who think they may be at risk should discuss this with their doctor. Possible risk factors for ALL include the following:
Painless lumps in the neck, underarm, stomach, or groin.
These and other symptoms may be caused by adult acute lymphoblastic
leukemia or by other conditions.
Tests that examine the blood and bone marrow are
used to detect (find) and diagnose adult ALL.
The following tests and procedures may be used:
Physical exam and history: An exam of the body to check general signs of health, including checking for signs of disease, such as lumps or anything else that seems unusual. A history of the patient's health habits and past illnesses and treatments will also be taken.
count (CBC): A procedure in which a sample of blood is drawn and
checked for the following:
Complete blood count (CBC). Blood is collected by inserting a needle into a vein and allowing the blood to flow into a tube. The blood sample is sent to the laboratory and the red blood cells, white blood cells, and platelets are counted. The CBC is used to test for, diagnose, and monitor many different conditions.
The number of red blood cells, white blood cells, and
The portion of the blood sample made up of red blood
Peripheral blood smear: A procedure in which a sample of blood is checked for the presence of blast cells, number and kinds of white blood cells, the number of platelets, and changes in the shape of blood cells.
Bone marrow aspiration and biopsy: The removal of bone marrow, blood, and a small piece of bone by inserting a hollow needle into the hipbone or breastbone. A pathologist views the bone marrow, blood, and bone under a microscope to look for abnormal cells.
Bone marrow aspiration and biopsy. After a small area of skin is numbed, a Jamshidi needle (a long, hollow needle) is inserted into the patient’s hip bone. Samples of blood, bone, and bone marrow are removed for examination under a microscope.
Cytogenetic analysis: A laboratory test in which the cells in a sample of blood or bone marrow are looked at under a microscope to find out if there are certain changes in the chromosomes in the lymphocytes. For example, sometimes in ALL, part of one chromosome is moved to another chromosome. This is called the Philadelphia chromosome. Other tests, such as fluorescence in situ hybridization (FISH), may also be done to look for certain changes in the chromosomes.
Philadelphia chromosome. A piece of chromosome 9 and a piece of chromosome 22 break off and trade places. The bcr-abl gene is formed on chromosome 22 where the piece of chromosome 9 attaches. The changed chromosome 22 is called the Philadelphia chromosome.
Immunophenotyping: A process used to identify cells, based on the types of antigens or markers on the surface of the cell. This process is used to diagnose the subtype of ALL by comparing the cancer cells to normal cells of the immune system. For example, a cytochemistry study may test the cells in a sample of tissue using chemicals (dyes) to look for certain changes in the sample. A chemical may cause a color change in one type of leukemia cell but not in another type of leukemia cell.
Certain factors affect prognosis (chance
of recovery) and treatment options.
The prognosis (chance of recovery) and treatment options depend on the following:
The age of the patient.
Whether the cancer has spread to the brain or spinal cord.
Whether the Philadelphia chromosome is present.
Whether the cancer has been treated before or has recurred (come back).