Hairy cell leukemia is a rare, slow-growing cancer of the blood in which your 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.
Common symptoms of HCL includes persistently feeling tired, weakness, weight loss for no reason, shortness of breath, excessive sweating (most often at night), swollen lymph nodes, frequent infections and fevers, small red spots on the skin. The main treatment for hairy cell leukemia is chemotherapy, purine analog drugs either cladribine (2-CdA) or pentostatin, monoclonal antibody rituximab, surgery or interferon alpha.
The disease occurs predominantly in middle-aged men, with a median age of 52 years. Hairy cell leukemia is relatively uncommon and accounts for 2% of all leukemia cases, which is about 600-800 new patients diagnosed each year. The overall remission rate was 80-85% at 10 years.