Definition

Hairy cell leukemia (HCL) is a rare form of cancer. It involves white blood cells called B lymphocytes. White blood cells protect the body from infection. HCL gets its name from the tiny hair-like projections that stick out of the surface of these cancer cells. Illness results from the build up of these cancer cells in the bone marrow and spleen.

Causes

Cancer occurs when cells in the body become abnormal. They divide without control or order. Leukemia is cancer of the white blood cells and their parent cells. Leukemia cells do not function normally. In this case, they can not fight infections. This means that the person is more likely to become infected with viruses or bacteria. The cancerous cells also overgrow the bone marrow. This forces other normal cells, like platelets out. Platelets are needed to help the blood clot. As a result, people with leukemia may bleed more easily.

The exact cause of HCL is unknown, but it may be linked to a genetic mutation.

Risk Factors

HCL occurs more often in men. It also occurs more often in people over the age of 50.

Symptoms

HCL usually develops slowly over time. Early on, there may not be any symptoms.

In those that have them, symptoms may include:

• Abdominal swelling
• Fever
• Easy bruising
• Night sweats
• Swollen lymph nodes

Diagnosis

You will be asked about your symptoms and medical history. A physical exam will be done.

Your bodily fluids and tissues may be tested. This can be done with:

• Blood tests
• Bone marrow biopsy

Images may be taken of your bodily structures with a CT scan.

Treatment

HCL is a slow-growing cancer. As HCL progresses, treatment may include:

• Surgery— A splenectomy may need to be done to remove an enlarged spleen.
• Chemotherapy —This

  is the use of drugs to kill cancer cells. It may be given in many forms. This includes pill, injection, and via a catheter. The drugs enter the bloodstream and travel through the body.

• Medications, such as cladribine, pentostatin, and interferon, are used to fight the hairy cells.
• Blood transfusion —A blood transfusion may be done to treat anemia.
• Antibiotics or other medications to fight infection.

Prevention

There are no guidelines for preventing HCL because the exact cause is unknown.

The Leukemia and Lymphoma Society http://www.leukemia.org

Canadian Cancer Society http://www.cancer.ca

Hairy cell leukemia. The Leukemia and Lymphoma Society website. Available at:
http://www.lls.org/#/diseaseinformation/leukemia/hairycellleukemia
Accessed November 26, 2013.

Hairy cell leukemia treatment (PDQ). National Cancer Institute website. Available at:
http://www.cancer.gov/cancertopics/pdq/treatment/hairy-cell-leukemia/Patient
Updated October 30, 2013. Accessed November 26, 2013.