7 Key Symptoms of Hairy Cell Leukemia You Should Know

Hairy cell leukemia (HCL) is a rare, slow-growing type of blood cancer in which the bone marrow produces too many B cells (lymphocytes), a type of white blood cell that fights infection. These abnormal cells have a “hairy” appearance under a microscope due to thin projections on their surface. While hairy cell leukemia progresses slowly, recognizing its symptoms early can lead to better management and outcomes. This condition typically affects middle-aged and older adults, with men being more commonly affected than women.

Understanding the symptoms of hairy cell leukemia is crucial because they can be subtle and develop gradually over time. Many people may not notice any symptoms in the early stages, and the condition is sometimes discovered during routine blood tests. However, as the disease progresses and abnormal cells accumulate in the bone marrow and spleen, various signs and symptoms may emerge.

1. Fatigue and Weakness

One of the most common and often earliest symptoms of hairy cell leukemia is persistent fatigue and weakness. This occurs because the cancerous hairy cells crowd out healthy blood cells in the bone marrow, leading to a reduction in red blood cells (anemia). Red blood cells are responsible for carrying oxygen throughout the body, and when their numbers decrease, the body’s tissues and organs don’t receive adequate oxygen.

Patients often describe this fatigue as feeling exhausted even after adequate rest, lacking energy to perform daily activities, or feeling unusually tired during routine tasks. The weakness may be particularly noticeable during physical activities that were previously manageable. Unlike normal tiredness that improves with rest, the fatigue associated with hairy cell leukemia tends to be persistent and may worsen over time as the disease progresses.

This symptom can significantly impact quality of life, making it difficult to maintain work productivity, engage in social activities, or exercise. If you experience unexplained, persistent fatigue that doesn’t improve with rest and lasts for several weeks, it’s important to consult with a healthcare provider.

2. Frequent Infections

People with hairy cell leukemia often experience recurrent infections due to a decreased number of normal white blood cells, particularly neutrophils, which are essential for fighting bacterial and fungal infections. As hairy cells accumulate in the bone marrow, they interfere with the production of healthy white blood cells, compromising the immune system’s ability to defend against pathogens.

These infections may manifest in various forms, including:

• Recurring respiratory infections such as pneumonia, bronchitis, or sinus infections
• Urinary tract infections that occur frequently or don’t respond well to treatment
• Skin infections, including cellulitis or abscesses
• Oral infections like thrush or mouth sores
• Fever without an obvious source

The infections may be more severe than usual, take longer to resolve, or require stronger antibiotics than would typically be necessary. Some patients may notice that they catch every cold or virus that circulates in their community, or that minor infections escalate into more serious conditions. This increased susceptibility to infections is a red flag that warrants medical evaluation.

3. Easy Bruising and Bleeding

Unusual or excessive bruising and bleeding episodes are telltale signs of hairy cell leukemia. This symptom occurs because the abnormal cells in the bone marrow reduce the production of platelets (thrombocytes), which are blood cells responsible for clotting. When platelet counts drop below normal levels (a condition called thrombocytopenia), the blood cannot clot properly.

Patients may notice several bleeding-related symptoms:

• Bruises appearing easily from minor bumps or without any remembered injury
• Bruises that are unusually large or take a long time to heal
• Small red or purple spots on the skin (petechiae) caused by bleeding under the skin
• Prolonged bleeding from minor cuts or dental procedures
• Frequent or severe nosebleeds
• Bleeding gums, especially when brushing teeth
• Heavy or prolonged menstrual periods in women
• Blood in urine or stool

These bleeding problems can range from mild to severe. While minor bruising may seem insignificant, it’s important to seek medical attention if you notice a pattern of easy bruising or bleeding, especially if accompanied by other symptoms.

4. Enlarged Spleen (Splenomegaly)

An enlarged spleen is one of the most characteristic features of hairy cell leukemia, occurring in approximately 80-90% of patients. The spleen, located in the upper left part of the abdomen, normally filters old blood cells and helps fight infection. In hairy cell leukemia, abnormal cells accumulate in the spleen, causing it to swell significantly beyond its normal size.

Symptoms of an enlarged spleen include:

• A feeling of fullness or discomfort in the upper left abdomen
• Pain in the upper left abdomen that may radiate to the left shoulder
• Feeling full after eating only a small amount of food (early satiety) because the enlarged spleen presses against the stomach
• A palpable mass that a doctor can feel during a physical examination
• Abdominal bloating or distension

In some cases, the spleen can become so enlarged that it causes significant discomfort or complications. The enlargement typically develops gradually, so patients may not notice the change until the spleen has grown considerably. An enlarged spleen can also trap and destroy blood cells prematurely, further worsening anemia, low platelet counts, and low white blood cell counts.

5. Unintentional Weight Loss

Unexplained weight loss is another common symptom of hairy cell leukemia. Patients may lose weight without trying, meaning they haven’t changed their diet or increased their physical activity. This weight loss can be attributed to several factors related to the disease.

The mechanisms behind weight loss in hairy cell leukemia include:

• Decreased appetite due to the enlarged spleen pressing on the stomach, causing early satiety
• Increased metabolic demands as the body tries to fight the cancer
• General malaise and fatigue that reduces interest in eating
• The cancer cells consuming nutrients that would normally be used by healthy tissues

The weight loss is typically gradual and may not be immediately noticeable, especially if it occurs over several months. However, losing 5% or more of body weight over a period of 6-12 months without intentional dietary changes or increased exercise should prompt a medical evaluation. Weight loss accompanied by other symptoms such as fatigue, infections, or abdominal discomfort is particularly concerning and warrants immediate attention.

6. Pale Skin (Pallor)

Paleness or pallor of the skin, mucous membranes, and nail beds is a visible sign of anemia commonly seen in hairy cell leukemia patients. As the disease reduces red blood cell production, the decreased oxygen-carrying capacity of the blood results in a paler appearance of the skin and tissues.

Areas where pallor is most noticeable include:

• The face, particularly the complexion appearing washed out or unusually pale
• The inside of the lower eyelids (conjunctiva)
• The nail beds, which may appear white or very pale pink
• The palms of the hands
• The mucous membranes, such as the inside of the mouth and gums
• The tongue, which may appear paler than usual

Pallor may be more difficult to detect in individuals with darker skin tones, but checking the mucous membranes can still reveal this symptom. Family members or friends who haven’t seen the patient in a while may be more likely to notice the change in complexion. Pallor often accompanies other symptoms of anemia, such as fatigue, weakness, and shortness of breath, and collectively these symptoms indicate that the blood’s oxygen-carrying capacity is compromised.

7. Shortness of Breath

Shortness of breath, medically known as dyspnea, is another symptom that can occur in hairy cell leukemia, particularly as anemia worsens. When red blood cell counts are low, the body’s tissues and organs, including the heart and muscles, don’t receive enough oxygen to function optimally.

Patients may experience:

• Difficulty breathing during activities that previously didn’t cause breathlessness, such as walking up stairs, doing household chores, or light exercise
• Feeling winded or out of breath after minimal exertion
• Rapid breathing or an increased respiratory rate
• A sensation of not being able to get enough air
• Needing to rest frequently during activities due to breathlessness
• Difficulty breathing when lying flat, requiring extra pillows to sleep comfortably

The shortness of breath typically develops gradually as anemia progresses. The heart tries to compensate for the reduced oxygen-carrying capacity by pumping faster and harder, which can lead to heart palpitations or a rapid heartbeat accompanying the breathlessness. While mild shortness of breath may be dismissed as being out of shape, progressive or persistent dyspnea, especially when accompanied by other symptoms like fatigue and pallor, requires medical evaluation.

Main Causes of Hairy Cell Leukemia

The exact cause of hairy cell leukemia remains unknown, and researchers have not identified specific risk factors that definitely lead to the disease. However, several factors and theories have been studied regarding the development of this rare cancer:

Genetic Mutations

Recent research has identified that nearly all cases of hairy cell leukemia involve a specific genetic mutation in the BRAF gene, specifically the BRAF V600E mutation. This mutation causes the B cells to grow and divide uncontrollably and live longer than normal cells. However, it’s unclear what triggers this mutation to occur. The mutation is acquired during a person’s lifetime rather than inherited from parents, which is why hairy cell leukemia is not considered a hereditary condition.

Age and Gender

While not a direct cause, hairy cell leukemia primarily affects middle-aged and older adults, with the average age of diagnosis being around 50-55 years. The disease is approximately four to five times more common in men than in women, though the reasons for this gender disparity are not well understood. These demographic patterns suggest that biological factors related to aging and sex may play a role in disease development.

Immune System Factors

Some researchers theorize that immune system dysfunction or chronic immune stimulation may contribute to the development of hairy cell leukemia, though concrete evidence is lacking. The fact that the disease affects B lymphocytes, which are integral to immune function, suggests that disruptions in immune regulation could be involved.

Environmental Factors

Unlike some other cancers, hairy cell leukemia has not been definitively linked to specific environmental exposures, radiation, chemicals, or lifestyle factors. Some studies have explored possible associations with agricultural work, exposure to certain chemicals, or radiation, but results have been inconsistent and inconclusive. The lack of clear environmental risk factors makes prevention strategies challenging.

It’s important to note that having one or more of these factors does not mean a person will develop hairy cell leukemia. The disease appears to develop due to a combination of random genetic changes in blood cells, and most people diagnosed have no identifiable risk factors.

Prevention Strategies

Unfortunately, because the exact causes of hairy cell leukemia are unknown and no specific risk factors have been definitively identified, there are no proven methods to prevent this disease. The genetic mutation that causes hairy cell leukemia (BRAF V600E) is acquired during a person’s lifetime rather than inherited, and it’s unclear what triggers this mutation.

However, maintaining overall health and early detection can be beneficial:

General Health Maintenance

While these practices won’t prevent hairy cell leukemia specifically, maintaining good overall health can help your body function optimally and may improve outcomes if disease develops:

• Eat a balanced, nutritious diet rich in fruits, vegetables, whole grains, and lean proteins
• Exercise regularly to maintain a healthy immune system and body weight
• Avoid tobacco products and limit alcohol consumption
• Get adequate sleep and manage stress effectively
• Limit exposure to known carcinogens when possible

Early Detection

Since prevention isn’t possible, focusing on early detection is important:

• Attend regular health check-ups and don’t skip routine blood work
• Report any unusual or persistent symptoms to your healthcare provider promptly
• Don’t dismiss subtle changes in your health, especially fatigue, recurrent infections, or unexplained bruising
• Be aware of your family health history and inform your doctor of any blood disorders in your family

If you experience any symptoms suggestive of hairy cell leukemia or any blood disorder, seeking medical attention early can lead to earlier diagnosis and better management of the condition.

Frequently Asked Questions

What is hairy cell leukemia?

Hairy cell leukemia is a rare, slow-growing cancer of the blood in which the bone marrow makes too many B cells (a type of white blood cell). These cells appear “hairy” under a microscope due to fine projections on their surface. It typically affects middle-aged and older adults, more commonly men than women.

How is hairy cell leukemia diagnosed?

Diagnosis typically involves several tests including complete blood count (CBC) to check blood cell levels, blood smear examination to identify hairy cells under a microscope, bone marrow biopsy to examine the bone marrow, flow cytometry to identify specific cell markers, and genetic testing to detect the BRAF V600E mutation. Sometimes it’s discovered incidentally during routine blood work.

Is hairy cell leukemia curable?

While hairy cell leukemia cannot always be completely cured, it is highly treatable and many patients achieve long-term remission lasting many years or even decades. Some patients may never need treatment if the disease is progressing very slowly and not causing symptoms. When treatment is needed, response rates are generally very good.

How fast does hairy cell leukemia progress?

Hairy cell leukemia is typically a slow-growing cancer. Some patients may have the disease for months or even years before symptoms develop or diagnosis is made. The progression rate varies among individuals, with some experiencing gradual worsening of symptoms while others remain stable for extended periods without treatment.

Who is at risk for hairy cell leukemia?

The disease most commonly affects middle-aged and older adults, with the average age at diagnosis around 50-55 years. Men are four to five times more likely to develop hairy cell leukemia than women. However, no specific lifestyle, environmental, or hereditary risk factors have been definitively identified, making it difficult to predict who will develop the disease.

Can hairy cell leukemia come back after treatment?

Yes, hairy cell leukemia can relapse after treatment, though many patients experience long remissions lasting years or decades. If the disease returns, it often responds well to additional treatment. Regular follow-up with blood tests and physical examinations is important to monitor for relapse and intervene early if needed.

What is the difference between hairy cell leukemia and other types of leukemia?

Hairy cell leukemia is distinguished by the characteristic appearance of the cancer cells under a microscope, the presence of the BRAF V600E mutation, its slow progression, and its tendency to enlarge the spleen. It’s much rarer than other leukemias and generally has a better prognosis with high treatment response rates and long survival times.

Should I see a doctor if I have these symptoms?

Yes, if you experience persistent fatigue, frequent infections, easy bruising or bleeding, unexplained weight loss, or discomfort in your upper left abdomen, you should consult a healthcare provider. While these symptoms can be caused by many conditions less serious than leukemia, it’s important to get evaluated. Early diagnosis leads to better outcomes and appropriate management of the condition.

References:

• National Cancer Institute – Hairy Cell Leukemia Treatment
• Mayo Clinic – Hairy Cell Leukemia
• American Cancer Society – Hairy Cell Leukemia
• Leukemia & Lymphoma Society – Hairy Cell Leukemia
• NHS – Hairy Cell Leukaemia