What is hairy cell leukemia (HCL)?
Hairy cell leukemia is the name of a type of chronic lymphoid leukemia, a subtype of blood malignancy or blood cancer. The name “hairy cell” is given to this subtype of leukemia due to hairlike projections found on the surface of aberrant B-cells. These are cytoplasmic projections, and the only way to see them and diagnose this subtype of leukemia is through a microscope. It is also diagnosed by the expression of certain surface antigens in B-cells that make up the differential diagnosis with similar diseases, such as multiple myeloma and chronic lymphocytic leukemia.