Hairy cell leukemia (HCL) is a rare type of blood and bone marrow cancer that affects the B-lymphocytes (a type of white blood cells that make antibodies that fight infections). If you have HCL, your body produces a surplus of abnormal B-lymphocytes that do not function properly. These abnormal cells can take up the space of healthy B-lymphocytes causing a low white blood cell count, which can weaken the immune system and lead to infections. While the production of abnormal B-lymphocytes is the hallmark of this disease, the increase production of these abnormal cells can cause a decrease in red blood cells as well as platelets. HCL gets its name because the abnormal white blood cells look hairy under a microscope. Rare cases of hairy cell leukemia affect T-lymphocytes (cells that help B-lymphocytes fight infection).
This type of cancer affects more men than women, and most HCL diagnoses are made in people over 50 years of age. According to the National Institutes of Health, people with HCL will likely live 10 years or longer after diagnosis (NIH, 2012).
While the exact cause of HCL is unknown, some research shows a relationship between the cancer and exposure to the herbicide Agent Orange, which was used to destroy crops and jungle canopy during the Vietnam War (IOM, 2009).
If you are a veteran who has HCL and were exposed to Agent Orange during the Vietnam War, you may qualify for disability and healthcare benefits from the United States Department of Veterans Affairs.
Common symptoms of HCL include:
- persistently feeling tired
- weight loss for no reason
- shortness of breath
- excessive sweating (most often at night)
- swollen lymph nodes
- frequent infections and fevers
- small red spots on the skin
- enlarged liver or spleen
- bruising and bleeding easily
- bone pain, especially under the ribs
HCL is a gradual disease that progresses slowly; in the early stages of HCL, you may experience few symptoms or none at all.
If you have HCL, it is important to keep an eye out for signs that the cancer is progressing. Call your doctor if you have a lot of bleeding, an infection, a persistent fever or cough, or generally do not feel well. These may be signs that your white blood cell count is low. Proper care and timely treatment is crucial for your health.
Your doctor may suspect HCL based on your symptoms, or if signs of the disease are present during a physical exam. Tests your doctor may perform to reach a diagnosis include:
- CT scan (CAT scan): A procedure that takes detailed images of your body and allows your doctor to view certain organs. People with HCL often have swelling of the spleen or liver.
- complete blood count: Measures the amount of white and red blood cells and platelets in your blood.
- peripheral blood smear: A test where your blood is viewed under a microscope to look for hairy cells.
- bone marrow biopsy: The doctor removes a small sample of your bone marrow using a hollow needle and views the sample under a microscope to look for signs of cancer.
- immunophenotyping: Your doctor looks at a sample of your blood cells or bone marrow under a microscope to look for certain markers (protein patterns) that are found on the surface of HCL cells.
Hairy cell leukemia is highly treatable. If your HCL is not progressing and if you do not have symptoms, your condition will be monitored but may not require immediate treatment.
You may need treatment if your normal blood cell counts are low, your spleen is swollen, or if you have an infection.
Common treatments include:
- blood transfusions to increase blood count
- chemotherapy treatments to kill abnormal cells
- surgery to remove a swollen spleen
- antibiotics to cure infection
Treatment will vary depending on the number of hairy cells and healthy cells in your blood and bone marrow, and whether you exhibit symptoms of HCL, such as a swollen or infected spleen. While some treatments may relieve and manage symptoms, none are known to cure HCL completely.
Treatment and recovery will depend on whether there is a continuous increase in the number of hairy cells and the rate at which these cells develop. Most cases of HCL respond well to treatment and usually result in long-term remission. Remission means that the cancer has stopped progressing and your symptoms have gone away. If the cancer begins to progress again and your symptoms return, retreatment may put the cancer back into remission.