Hairy Cell Leukemia (HCL) (Leukemic Reticuloendotheliosis)

Definition

Hairy cell leukemia (HCL) is a rare form of cancer involving white blood cells called B lymphocytes. White blood cells protect the body from infections and cancers. HCL gets its name from the tiny hair-like projections that protrude from the surface of HCL cancer cells. Illness results from the accumulation of these cancer cells in the bone marrow and spleen.

Cancer occurs when cells in the body (in this case white blood cells) divide without control or order. Normally, cells divide in a regulated manner. If cells keep dividing uncontrollably when new cells are not needed, a mass of tissue forms, called a growth or tumor. The term cancer refers to malignant tumors, which can invade nearby tissue and can spread to other parts of the body. A benign tumor usually does not invade or spread.

Causes

The exact cause of HCL is unknown.

Risk Factors

A risk factor is something that increases your chance of getting a disease or condition. Specific risk factors for HCL are unknown. However, the disease tends to occur more often in men and in people over the age of 50.

Symptoms

HCL tends to develop slowly over a number of years. It often causes no symptoms at first. Eventually, the accumulation of cancer cells interferes with the normal function of the bone marrow, which often leads to a deficiency of red blood cells ( anemia ), white blood cells, and platelets.

Symptoms may include:

• Weakness and fatigue (due to anemia)
• Enlarged spleen
• Enlarged liver
• Recurrent infections, often with fevers (due to low white cell count)
• Ease in bruising and bleeding (due to low platelet count)
• Night sweats
• Swollen lymph nodes (rare)

Diagnosis

The doctor will ask about your symptoms and medical history, and perform a physical exam. Tests may include:

• Blood tests
• Bone marrow biopsy —removal of a sample of bone marrow tissue to test for cancer cells
• CT scan —a type of x-ray that uses a computer to make pictures of the spleen and the liver

Treatment

HCL is a slow-growing cancer that does not require aggressive treatment early on. As HCL progresses, treatment may include:

Prevention

There are no guidelines for preventing HCL because the exact cause is unknown.