Causes

HCL is caused by the abnormal growth of B cells. The cells look "hairy" under the microscope because they have fine projections coming from their surface.

HCL can lead to low numbers of normal blood cells.

The cause of this disease is unknown. It affects men more often than women. The average age of diagnosis is 55.

Symptoms

• Easy bruising or bleeding
• Excessive sweating (especially at night)
• Fatigue
• Feeling full after eating only a small amount
• Recurrent infections and fevers
• Swollen lymph glands
• Weakness
• Weight loss

Exams and Tests

During a physical exam, the doctor may be able to feel a swollen spleen or liver. An abdominal CT scan may be done to evaluate this swelling.

A complete blood count usually shows low levels of white and red blood cells as well as platelets.

Blood tests and a bone marrow biopsy can detect hairy cells. Flow cytometry or a test called tartrate resistant acid phosphatase (TRAP) can confirm the cancer diagnosis.

Treatment

Treatment may not be needed for the early stages of this disease. Some patients may need an occasional blood transfusion.

If treatment is needed because of very low blood counts, a variety of chemotherapy drugs can be used. A drug called cladribine is used. In most cases, chemotherapy can relieve the symptoms for many years. (When the signs and symptoms go away, you are said to be in remission.) Interferon can relieve symptoms but is unlikely to lead to remission.

Removing the spleen may improve blood counts, but is unlikely to cure the disease. Antibiotics can be used to treat infections. People with low blood counts will receive growth factors and, possibly, transfusions.

Outlook (Prognosis)

Newer chemotherapy treatments have greatly improved the survival of patients with hairy cell leukemia. Most patients with hairy cell leukemia can expect to live 10 years or longer after diagnosis.

Possible Complications

The low blood counts caused by hairy cell leukemia can lead to infections, fatigue, and excessive bleeding.

When to Contact a Medical Professional

Call your health care provider if you have significant bleeding. Also call if you have signs of infection, such as a persistent fever, cough, or general ill feeling.

Prevention

There is no known way to prevent this disease.

Alternative Names

Leukemic reticuloendotheliosis; HCL; Leukemia - hairy cell

References

Kantarjian H, O’Brien S. The chronic leukemias. In Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007: chap 195.

Updated: 4/6/2012

Reviewed by: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine; James R. Mason, MD, Oncologist, Director, Blood and Marrow Transplantation Program and Stem Cell Processing Lab, Scripps Clinic, Torrey Pines, California. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.