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.
1 Hairy cell leukemia is an uncommon type of chronic leukemia. 2  Chronic myelomonocytic leukemia (CMML) is another type of chronic leukemia that develops from myeloid cells.  Juvenile myelomonocytic leukemia (JMML) is a type of myeloid leukemia that usually occurs in children under 6 years of age.