Hairy Cell Leukemia
What is Hairy Cell Leukemia?
Hairy cell leukemia is a rare type of blood cancer that grows slowly in your bone marrow and blood. It gets its name from how the cancer cells look under a microscope. They have tiny hair-like projections on their surface.
This condition affects a type of white blood cell called B lymphocytes. These cells normally help your immune system fight infection. In hairy cell leukemia, abnormal B cells multiply and crowd out healthy blood cells. This can lead to low counts of red blood cells, white blood cells, and platelets.
Hairy cell leukemia is uncommon and affects more men than women. Most people are diagnosed after age 50. The condition progresses slowly, and many people live for years with proper treatment. Early detection through blood testing helps doctors monitor the disease and start treatment when needed.
Symptoms
- Fatigue and weakness from low red blood cell counts
- Frequent infections due to reduced healthy white blood cells
- Easy bruising or bleeding from low platelet levels
- Swollen abdomen from an enlarged spleen
- Feeling full quickly when eating
- Unintentional weight loss
- Night sweats
- Fever without infection
- Pain or fullness below the ribs on the left side
Some people with hairy cell leukemia have no symptoms at first. The condition may be discovered during routine blood work for another reason. As the disease progresses, symptoms typically become more noticeable as healthy blood cell counts drop.
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Causes and risk factors
The exact cause of hairy cell leukemia remains unknown. Researchers have found that nearly all cases involve a specific genetic change called a BRAF mutation. This mutation happens in the DNA of B lymphocytes and causes them to grow and divide abnormally. The mutation is not inherited from parents. It develops during a person's lifetime.
Risk factors include being male, being over age 50, and possible exposure to certain chemicals or radiation. However, most people with hairy cell leukemia have no clear risk factors. The condition is not linked to lifestyle choices like diet or exercise. Family history does not appear to play a major role in most cases.
How it's diagnosed
Doctors diagnose hairy cell leukemia through blood tests and bone marrow examination. A complete blood count often shows low levels of red blood cells, white blood cells, and platelets. A key finding is very low monocyte counts, often below 200 cells per microliter. Looking at blood cells under a microscope reveals the characteristic hairy appearance of abnormal lymphocytes.
Testing for the BRAF mutation helps confirm the diagnosis in almost all cases. This genetic test identifies the specific change that drives the cancer. Rite Aid offers blood testing that includes lymphocyte and monocyte evaluation, which are essential for detecting this condition. Your doctor may also perform a bone marrow biopsy to see how many hairy cells are present and assess disease severity.
Treatment options
- Active monitoring with regular blood tests if the disease is not causing symptoms
- Chemotherapy drugs like cladribine or pentostatin when treatment is needed
- Targeted therapy with BRAF inhibitors for resistant cases
- Spleen removal in some cases of severe enlargement
- Antibiotics to prevent or treat infections when white blood cell counts are low
- Blood transfusions if red blood cells or platelets become dangerously low
- Regular follow-up appointments to monitor blood counts and disease progression
- Nutritious diet to support overall health and immune function
- Adequate rest and stress management to help your body cope
Concerned about Hairy Cell Leukemia? Get tested at Rite Aid.
- Simple blood draw at your nearest lab
- Results in days, not weeks
- Share results with your doctor
Frequently asked questions
Hairy cell leukemia is a rare, slow-growing cancer with distinctive features. The cancer cells have hair-like projections visible under a microscope. Nearly all cases involve a BRAF mutation. Another unique feature is extremely low monocyte counts, often below 200 cells per microliter, which helps doctors distinguish it from other leukemias.
Hairy cell leukemia is quite rare. It accounts for only about 2 percent of all leukemia cases. Roughly 1,000 new cases are diagnosed in the United States each year. Men are four times more likely than women to develop this condition, and most cases occur in people over age 50.
Yes, hairy cell leukemia is often first detected during routine blood tests. A complete blood count may show unusually low levels of red blood cells, white blood cells, and platelets. Very low monocyte counts are a particularly important clue. Your doctor will order additional tests if these patterns appear in your results.
The BRAF mutation is a genetic change found in nearly all hairy cell leukemia cases. This mutation causes B lymphocytes to grow and divide abnormally. Testing for this mutation helps confirm the diagnosis and can guide treatment decisions. The mutation develops during your lifetime and is not inherited from parents.
Not always. Many people with hairy cell leukemia do not need immediate treatment. If your blood counts are stable and you have no symptoms, your doctor may recommend active monitoring with regular blood tests. Treatment usually begins when blood counts drop significantly or symptoms develop.
Treatment is very effective for most people with hairy cell leukemia. Chemotherapy drugs like cladribine and pentostatin produce complete remission in 80 to 90 percent of patients. Many people remain in remission for years or even decades. If the disease returns, additional treatment options are available.
Low monocyte counts are a hallmark feature of hairy cell leukemia. Monocytes are a type of white blood cell that fights infection. In this condition, monocyte counts often drop below 200 cells per microliter. This finding helps doctors distinguish hairy cell leukemia from other blood cancers that may look similar.
While lifestyle changes cannot cure hairy cell leukemia, they support overall health during treatment. Eating a nutritious diet helps maintain strength and supports your immune system. Getting adequate rest and managing stress can help your body cope with the disease. Regular exercise, as tolerated, may improve energy levels and well-being.
The spleen filters blood and removes old or damaged cells. In hairy cell leukemia, abnormal cells accumulate in the spleen. This causes the organ to swell beyond its normal size. An enlarged spleen can cause abdominal discomfort and a feeling of fullness after eating small amounts of food.
Testing frequency depends on your treatment status and disease activity. If you are being monitored without treatment, blood tests every three to six months are typical. During and after treatment, more frequent testing helps assess response. Your doctor will create a monitoring schedule based on your individual situation and blood count stability.