In hairy cell leukemia, too many blood stem cells become lymphocytes. These lymphocytes are abnormal
and do not become healthy white blood cells. They are also called leukemia cells. The leukemia cells can build up in the blood and bone marrow so there is less room for healthy white blood cells, red blood cells, and platelets. This may cause infection, anemia, and easy bleeding. Some of the leukemia cells may collect in the spleen
and cause it to swell.
This summary is about hairy cell leukemia.
See the following PDQ
summaries for information about other types of leukemia:
Gender and age may affect the risk of hairy cell leukemia.
Anything that increases your chance 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. The cause of hairy cell leukemia is unknown. It occurs more often in older men.
Signs and symptoms of hairy cell leukemia include infections, tiredness, and pain below the ribs.
These and other signs
may be caused by hairy cell leukemia or by other conditions.
Check with your doctor if you have any of the following:
Tests that examine the blood and bone marrow are used to detect
(find) and diagnose hairy cell leukemia.
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 a swollen spleen, lumps, or anything else that seems unusual. A history of the patient’s health habits and past illnesses and treatments will also be taken.
(CBC): A procedure in which a sample of blood is drawn and
checked for the following:
The number of red blood cells, white blood cells, and
The portion of the sample made up of red blood
Peripheral blood smear: A procedure in which a sample of blood is checked for cells that look "hairy," the number and kinds of white blood cells, the number of platelets, and changes in the shape of 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.
Immunophenotyping: A laboratory test
in which the antigens
on the surface of a blood or bone marrow cell are checked to see what type of cell it is. This test is done to diagnose
the specific type of leukemia by comparing the cancer cells to normal cells of the immune system.
Flow cytometry: A laboratory test
that measures the number of cells in a sample, the percentage of live cells in a sample, and certain characteristics of cells, such as size, shape, and the presence of tumor markers
on the cell surface. The cells are stained with a light-sensitive dye, placed in a fluid, and passed in a stream before a laser
or other type of light. The measurements are based on how the light-sensitive dye reacts to the light.
Cytogeneticanalysis: A laboratory test in which cells in a sample of tissue are viewed under a microscope to look for certain changes in the chromosomes.
test: A laboratory test done on a bone marrow or blood sample to check for mutations in the BRAF gene. A BRAF gene mutation is often found in patients with hairy cell leukemia.
(CAT scan): A procedure that makes a series of detailed pictures of areas inside the body, taken from different angles. The pictures are made by a computer linked to an x-ray
machine. A dye may be injected
into a vein
or swallowed to help the organs or tissues show up more clearly. This procedure is also called computed tomography, computerized tomography, or computerized axial tomography. A CT scan of the abdomen
may be done to check for swollen lymph nodes
or a swollen spleen.
Certain factors affect treatment options and prognosis (chance
The treatment options may depend on the following:
The number of hairy (leukemia) cells and healthy blood cells in the blood and bone marrow.
Whether the spleen is swollen.
Whether there are signs or symptoms of leukemia, such as infection.
Whether the leukemia has recurred
(come back) after previous treatment.
Whether the hairy cell leukemia does not grow or grows so slowly it does not need treatment.
Whether the hairy cell leukemia responds
Treatment often results in a long-lasting remission
(a period during which some or all of the signs and symptoms of the leukemia are gone). If the leukemia returns after it has been in remission, retreatment often causes another remission.
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