Mondo Description Hairy cell leukemia (HCL) is a rare type of leukemia in which abnormal B-lymphocytes are present in the bone marrow, spleen and peripheral blood. It is a slowly progressive chronic lymphocytic leukemia (CLL). The name comes from the abnormally shaped lymphocytes with hair-like projections.

Disease Ontology Description A chronic lymphocytic leukemia that is characterized by over production of B cells (lymphocytes) by the bone marrow where the B cells appear hairy under a microscope.