Hairy cell leukemia

Hairy_cell_leukemia.jpg

Hairy cell leukemia (HCL) is a rare, slow-growing cancer of the blood in which the bone marrow makes too many B cells (lymphocytes), a type of white blood cell that fights infection. These excess B cells are abnormal and look "hairy" under a microscope due to fine projections from their surface.

Signs and Symptoms

Patients with hairy cell leukemia may experience a variety of symptoms, including:

• Fatigue
• Weakness
• Weight loss
• Frequent infections
• Easy bruising or bleeding
• Splenomegaly (enlarged spleen)
• Hepatomegaly (enlarged liver)

Diagnosis

The diagnosis of hairy cell leukemia typically involves several tests, including:

• Complete blood count (CBC)
• Peripheral blood smear
• Bone marrow biopsy
• Flow cytometry
• Immunophenotyping

Pathophysiology

Hairy cell leukemia is characterized by the accumulation of abnormal B cells in the bone marrow, spleen, and peripheral blood. These cells have a distinct appearance with hair-like projections. The exact cause of HCL is unknown, but it is associated with mutations in the BRAF gene, particularly the BRAF-V600E mutation.

Treatment

Treatment options for hairy cell leukemia include:

• Chemotherapy (e.g., cladribine, pentostatin)
• Immunotherapy (e.g., rituximab)
• Targeted therapy (e.g., vemurafenib for BRAF-mutated HCL)
• Splenectomy (surgical removal of the spleen) in certain cases

Prognosis

The prognosis for patients with hairy cell leukemia is generally favorable, especially with appropriate treatment. Many patients achieve long-term remission. However, the disease can relapse, and ongoing monitoring is necessary.

Epidemiology

Hairy cell leukemia is more common in men than in women and typically affects middle-aged to older adults. It is a rare disease, accounting for approximately 2% of all leukemias.

See Also

• Leukemia
• Chronic lymphocytic leukemia
• Lymphoma
• Bone marrow