Hairy Cell Leukemia

What is hairy cell leukemia?

Hairy cell leukemia is a rare type of blood cancer that happens when your bone marrow makes abnormal B-cells (B lymphocytes). These are a type of white blood cells that fight infections. The name of the condition comes from the tiny hair-like protrusions on the abnormal B-cells, which pathologists can see when they look at the cells under a microscope.

You have B lymphocytes in your bone marrow, lymph nodes and spleen. Hairy cell leukemia symptoms happen when your normal B lymphocytes change into abnormal ones. When that happens:

• Abnormal cells in your bone marrow act like weeds taking over a vegetable garden. They take up so much space in your bone marrow that there’s no room for healthy white blood cells, red blood cells and platelets.
• Cells in your lymph nodes and spleen divide and multiply, making them swell.
• Cells in your bloodstream may spread to your liver, causing damage that leads to ascites (fluid buildup in your belly).

How common is hairy cell leukemia?

Hairy cell leukemia is a rare condition that affects 1 in 100,000 people in the U.S.

The condition affects men and people assigned male at birth (AMAB) more than women and people assigned female at birth (AFAB). It’s more common in people who are white than people in other ethnic groups.

What are the symptoms of hairy cell leukemia?

Hairy cell leukemia may not cause symptoms. But when it does, symptoms may include:

• Fatigue: This can happen if you have anemia (low red blood cell levels).
• Fever and frequent infections: You can develop serious infections that cause fevers because you don’t have enough infection-fighting white blood cells.
• Pain in your lower left side: Abnormal cells in your spleen may make your spleen swell so there’s pain on your left side. Your spleen may press on your abdomen (belly) so that you feel full even when you aren’t eating a lot of food. You may lose weight without trying.
• Pain in your lower right side: Your liver may get larger and cause pain on your right side.
• Shortness of breath: This is another anemia symptom from low red blood cell levels.
• Swollen lymph nodes: These are painless lumps in your neck, underarms and stomach.
• Unusual bruising or bleeding: Hairy cell leukemia keeps your bone marrow from making enough platelets, which helps slow or stop bleeding.

What causes hairy cell leukemia?

Experts don’t know the exact cause. Research shows that 90% of people with hairy cell leukemia have a genetic mutation (change) that affects the BRAF gene. This gene helps cell growth. When it changes, it creates abnormal cells that grow and multiply uncontrollably. This change happens after you’re born. Researchers aren’t sure what triggers the change, but there are risk factors that increase your chance of developing hairy cell leukemia.

Risk factors

Hairy cell leukemia risk factors include:

• Your age: This condition often affects people ages 40 to 70. On average, most of the people with hairy cell leukemia are 58 when they receive a diagnosis.
• Your sex: The condition affects people assigned male at birth (AMAB) more than people assigned female at birth (AFAB).
• Exposure to Agent Orange: Researchers believe there’s a link between this chemical and chronic B-cell leukemias and lymphomas, including hairy cell leukemia.

What are the complications of hairy cell leukemia?

This condition increases your risk of infections because you have very low levels of infection-fighting white blood cells. These include bacterial infections, viral infections or fungal infections that may be life-threatening.

There’s also a small chance that you’ll develop another type of cancer (secondary cancer) years after you receive your diagnosis and treatment.

For example, researchers following up on people with hairy cell leukemia found some people had cancerous tumors that appeared 10 to 20 years after successful treatment for the condition.

How is hairy cell leukemia diagnosed?

Healthcare providers will ask when your symptoms started and take a medical history, including whether you have infections that keep coming back. They’ll also do a physical examination. They may feel (palpitate) your lymph nodes, spleen and liver for signs of swelling.

They may refer you to a hematologist or medical oncologist for more tests that will lead to a diagnosis. These tests may include:

• Complete blood count (CBC) with differential: This test measures the number of red and white blood cells and platelets. The differential measures the different types of white blood cells.
• Peripheral blood smear: Pathologists examine blood cells under a microscope, looking for abnormal cells that have the tiny hair-like projections that give hairy cell leukemia its name.
• Bone marrow aspiration and bone marrow biopsy: These tests detect abnormal cells in your bone marrow.
• Computed tomography (CT) scan: CT scans make detailed pictures of areas inside your body. Your provider may order this test or an abdominal ultrasound to check the size of your spleen, liver and lymph nodes.
• Flow cytometry: Pathologists check your blood and bone marrow for signs of abnormal hairy cells. They check the cells’ size and shape and look for tumor markers. Tumor markers may refer to proteins that cancerous cells make.

How is hairy cell leukemia treated?

You might need immediate treatment for an infection and then other treatments to manage symptoms of hairy cell leukemia. But the condition doesn’t always cause symptoms. In that case, your hematologist or oncologist may recommend active surveillance. If you have symptoms, they may recommend medication.

Active surveillance

Hairy cell leukemia grows very slowly. You may have it for years before developing symptoms. Cancer treatment comes with side effects and potential complications. If you don’t have symptoms, your oncologist may recommend delaying treatment until you develop symptoms.

In active surveillance, you’ll see your oncologist every three to six months. During those checkups, they’ll:

• Ask about your overall health, particularly if you’re feeling more tired than usual.
• Do a physical examination, checking your liver and spleen for signs of swelling.
• Order blood tests to check your blood cell and platelet levels.

It can be stressful to wait for symptoms to develop before starting treatment. Your oncologist will understand your feelings and will be glad to explain why they recommend active surveillance.

Medication

Chemotherapy is the most common initial (first-line) treatment for people who have symptoms with hairy cell leukemia. Cladribine (Leustatin^®) or pentostatin (Nipent^®) are common initial anticancer drug treatments for this condition.

You may have other treatments for hairy cell leukemia if chemotherapy isn’t effective or the condition comes back. Treatment options include:

• Immunotherapy: Rituximab (Rituxan^®) is a monoclonal antibody treatment for hairy cell leukemia. Your provider may combine this treatment with chemotherapy as initial treatment or if the disease comes back after treatment. Another type of immunotherapy is recombinant Interferon Alfa-2b (Intron A^®).
• Targeted therapy: Oncologists may treat recurrent hairy cell leukemia with rituximab and moxetumomab pasudotox (Lumoxiti^®), a type of antibody-drug conjugate.
• Splenectomy: Rarely, your provider may recommend this procedure if medical treatments like chemotherapy aren’t effective and abnormal cells in your spleen continue to make it swell.

Treatment complications and side effects

All cancer treatments have side effects. In this case, the chemotherapy drugs that treat hairy cell leukemia increase your risk of infections that may be life-threatening. Your oncologist will explain what steps you can take to prevent infections. They’ll also tell you what changes in your body may be signs you have an infection.

What can I expect if I have hairy cell leukemia?

There’s no cure for hairy cell leukemia. Research shows treatment, including chemotherapy, can put this condition into remission for 10 years or more. Remission means you don’t have symptoms anymore and tests don’t find any signs of the condition. One analysis of people’s experience with hairy cell leukemia suggests that, after treatment, they’ll live as long as people who don’t have the condition.

That said, hairy cell leukemia can come back after several years of initial treatment. But there are treatments to put the disease back into remission.

Most people need medical care and support for the rest of their lives so their providers can watch for recurrent hairy cell leukemia. If you have this disease but don’t have symptoms, you’ll have checkups and tests every three to six months after your diagnosis.

What’s the survival rate for hairy cell leukemia?

According to the Leukemia and Lymphoma Society, 90% of people treated with the chemotherapy drug cladribine were alive five years after treatment. But your prognosis (what may happen after treatment), depends on many factors. Your age, your overall health, your symptoms and your body’s response to treatment all play a part in your prognosis. If you have questions about your survival rate, ask your oncologist to explain how survival rate data applies to you.

How do I take care of myself?

Hairy cell leukemia increases the chance you’ll develop infections that can be life-threatening. You can strengthen your immune system and protect yourself from infection. Here are some suggestions:

• Fill your plate with healthy foods: Fruits, veggies, lean sources of protein and whole grains are just some examples of foods that bolster immune function.
• Build activity into your daily routine: Daily activity helps many aspects of your health, including your immune system.
• Catch enough ZZZs: Not getting enough sleep can prevent your immune system from working as it should.
• Stay up-to-date on vaccines: Vaccines train your body to fight off germs that can make you sick. Talk to your provider about which vaccines you need and when.

When should I see my healthcare provider?

Hairy cell leukemia and treatments increase the chance you’ll have serious and sometimes life-threatening infections. Contact your healthcare provider if you have the following symptoms:

• A fever above 100.4 degrees Fahrenheit (38 degrees Celsius) that doesn’t go away.
• A sore throat that lasts longer than a few days or gets worse.
• Abdominal pain that doesn’t go away or gets worse.