In ALL, too many stem cells become lymphoblasts, B lymphocytes, or T lymphocytes. These cells are also called leukemia
cells. These leukemia cells are not able to fight infection very well. Also, as the number of leukemia 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 about 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. Talk with your doctor if you think you may be at risk. Possible risk factors for ALL include the following:
These and other signs and 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:
and history: An exam of the body to check general signs of health, including checking for signs of disease, such as infection or anything else that seems unusual. A history of the patient's health habits and past illnesses and treatments will also be taken.
The portion of the blood sample made up of red blood cells.
Blood chemistry studies: A procedure in which a blood sample is checked to measure the amounts of certain substances released into the blood by organs
and tissues in the body. An unusual (higher or lower than normal) amount of a substance can be a sign of disease.
Peripheral blood smear: A procedure in which a sample of blood is checked for blast
cells, the number and kinds of white blood cells, the number of platelets, and changes in the shape of blood cells.
The following tests may be done on the samples of blood or bone marrow tissue that are removed:
Cytogeneticanalysis: 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
of lymphocytes. For example, in Philadelphia chromosome
–positive ALL, part of one chromosome switches places with part of another chromosome. This is called the “Philadelphia chromosome.”
Immunophenotyping: A process used to identify cells, based on the types of antigens
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.