What is Hairy Cell Leukemia?

Hairy cell leukemia (HCL) is a rare blood disorder that was first reported at Ohio State University in 1958. HCL is a chronic leukemia and does not develop into acute leukemia. The name "hairy cell" describes the abnormally shaped white blood cells with hair-like projections that characterize this disorder. Most patients diagnosed with HCL are male with a median age of 52. However, with more widespread knowledge of the disease and better diagnostic techniques, physicians have identified HCL in both sexes and among younger adults.

The disease is usually gradual in onset. Symptoms of HCL generally center around the disruption of normal blood cell production. Many patients are diagnosed at the time of a routine blood count check and are found to have abnormally low blood counts. Other patients come to medical attention because of fatique or shortness of breath related to anemia, abdominal discomfort or early satiety when they eat because of an enlarged spleen or bleeding or bruising due to a low platelet count. Rarely, patients may present to a physician because of infection related to a low white blood cell count. Diagnosis is confirmed by results of a bone marrow biopsy.

While the cause of HCL is not known, it is treatable and the long term prognosis for most HCL patients is excellent.