Last Modified : 2005-05-12
Hairy cell leukemia is a cancer of the blood and bone marrow. This rare type of leukemia gets worse slowly or not at all. The disease is called hairy cell leukemia because the leukemia cells look "hairy" when viewed under a microscope.
Normally, the bone marrow produces stem cells (immature cells) that develop into mature blood cells. There are 3 types of mature blood cells:
In hairy cell leukemia, too many stem cells develop into a type of white blood cell called lymphocytes. These lymphocytes may also be called leukemic cells. There are 3 types of lymphocytes.
In hairy cell leukemia, the B lymphocytes do not work normally. Also, as the number of lymphocytes 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. Some of the leukemia cells may collect in the spleen and cause it to swell.
This summary is about hairy cell leukemia. Refer to the following PDQ summaries for information about other types of leukemia:
The cause of hairy cell leukemia is unknown. It occurs more often in older men.
Possible signs of hairy cell leukemia include tiredness, infections, and pain below the ribs.These and other symptoms may be caused by hairy cell leukemia. Other conditions may cause the same symptoms. A doctor should be consulted if any of the following problems occur:
The following tests and procedures may be used:
The treatment options may depend on the following:
The prognosis (chance of recovery) depends on the following:
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.
Staging is the process used to find out how far the cancer has spread. There is no standard staging system for hairy cell leukemia. The disease is grouped as untreated, progressive, or refractory.
Untreated hairy cell leukemia
The hairy cell leukemia is newly diagnosed and has not been treated except to relieve symptoms such as weight loss and infections. In untreated hairy cell leukemia, some or all of the following conditions occur:
Progressive hairy cell leukemia
In progressive hairy cell leukemia, the leukemia has been treated with either chemotherapy or splenectomy (removal of the spleen) and one or both of the following conditions occur:
Relapsed hairy cell leukemia has come back after treatment. Refractory hairy cell leukemia has not responded to treatment.
Different types of treatment are available for patients with hairy cell leukemia. Some treatments are standard (the currently used treatment), and some are being tested in clinical trials. Before starting treatment, patients may want to think about taking part in a clinical trial. A treatment clinical trial is a research study meant to help improve current treatments or obtain information on new treatments for patients with cancer. When clinical trials show that a new treatment is better than the standard treatment, the new treatment may become the standard treatment.
Clinical trials are taking place in many parts of the country. Information about ongoing clinical trials is available from the NCI Web site. Choosing the most appropriate cancer treatment is a decision that ideally involves the patient, family, and health care team.
Four types of standard treatment are used:Watchful waiting is closely monitoring a patient's condition, without giving any treatment until symptoms appear or change.
ChemotherapyChemotherapy is a cancer treatment that uses drugs to stop the growth of cancer cells, either by killing the cells or by stopping the cells from dividing. When chemotherapy is taken by mouth or injected into a vein or muscle, the drugs enter the bloodstream and can reach cancer cells throughout the body (systemic chemotherapy). When chemotherapy is placed directly into the spinal column, an organ, or a body cavity such as the abdomen, the drugs mainly affect cancer cells in those areas (regional chemotherapy). The way the chemotherapy is given depends on the type and stage of the cancer being treated. Cladribine and pentostatin are anticancer drugs commonly used to treat hairy cell leukemia.
Biologic therapyBiologic therapy is a cancer treatment that uses the patient’s immune system to fight cancer. Substances made by the body or made in a laboratory are used to boost, direct, or restore the body’s natural defenses against cancer. This type of cancer treatment is also called biotherapy or immunotherapy. Interferon alfa is a biologic agent commonly used to treat hairy cell leukemia. For relapsed or refractory patients, a biologic agent called rituximab may be used.
SurgerySplenectomy is a surgical procedure to remove the spleen.
Other types of treatment are being tested in clinical trials. These include the following:Stem cell transplant is a method of giving chemotherapy and replacing blood-forming cells destroyed by the cancer or cancer treatment. Stem cells (immature blood cells) are removed from the blood or bone marrow of a brother or sister and are frozen and stored. After the chemotherapy is completed, the stored stem cells are thawed and given back to the patient through an infusion. These reinfused stem cells grow into (and restore) the body’s blood cells.
This summary section refers to specific treatments under study in clinical trials, but it may not mention every new treatment being studied. Information about ongoing clinical trials is available from the NCI Web site.
If the patient's blood cell counts are not too low and there are no symptoms, treatment may not be needed and the patient is carefully watched for changes in his or her condition. If blood cell counts become too low or symptoms appear, initial treatment may include the following:
Treatment for progressive hairy cell leukemia may include the following:
Treatment of relapsed or refractory hairy cell leukemia may include the following:
This summary section refers to specific treatments under study in clinical trials, but it may not mention every new treatment being studied. Information about ongoing clinical trials is available from the NCI Web site.