What is hairy cell leukemia?
Hairy cell leukemia (abbreviated as HCL) is a rare cancer of the blood and bone marrow. In this form of cancer, certain types of white blood cells, called B-lymphocyte cells, are affected. Hairy cell leukemia is characterized by the uninhibited growth of these B-lymphocytes and low numbers of other normal blood cells. The abnormal cells have fine outgrowths on their surface giving them a hairy look when viewed with a microscope, which is the reason for the name of the condition.