The Global Hairy Cell Leukemia Market Size is Expected to Grow from USD 92.1 Billion in 2023 to USD 155.2 Billion by 2033, at a CAGR 5.36% during the forecast period 2023-2033. Hairy Cell Leukemia (HCL) is a rare, indolent blood cancer of the B cells, a group of white blood cells. It is defined by the presence of abnormal, "hairy"-appearing lymphocytes in the bone marrow, spleen, and blood that reduce blood counts, and cause tiredness, infection, and an enlarged spleen.