Learn about the three most important lines of latitude on Earth - the equator, Tropic of Cancer, and Tropic of Capricorn. Learn about the three most important lines of latitude on Earth - the equator, Tropic of Cancer, and Tropic of Capricorn.
General Discussion. Hairy cell leukemia (HCL) is a rare type of blood cancer characterized by abnormal changes in white blood cells known as B lymphocytes. The bone marrow creates too many of these defective cells, known as hairy cells because of the thin hair-like projections found on their surface.
Hairy cell leukemia. Hairy cell leukemia (HCL) is a rare subtype of chronic lymphocytic leukemia (CLL) that progresses slowly. HCL is caused when bone marrow makes too many B cells (lymphocytes), a type of white blood cell that fights infection. As the number of leukemia cells increases, fewer healthy white blood cells, red blood cells and platelets are produced.