title: Chronic lymphoid leukemias: recent advances in biology and therapy.
abstract: There exists a wide variety of lymphoid leukemias derived from B and T lymphocytes. These diseases have distinct immunologic and biologic features as well as varied responses to therapeutics. The most common lymphoid leukemia is chronic lymphocytic leukemia (CLL) which is a clonal proliferation of a subset of B cells expressing the CD5 antigen. Prolymphocytic leukemia is usually derived from B cells and shares some features with CLL but is clearly a distinct entity. Hairy-cell leukemia is a B cell malignancy that is uniquely responsive to a variety of biologic and chemotherapeutic agents. Waldenström's macroglobulinemia is a B cell malignancy that secretes immunoglobulin M (IgM) and may present with the hyperviscosity syndrome. Other B cell malignancies that less commonly present as leukemias include non-Hodgkin's lymphomas such as follicular lymphoma or mantle zone lymphoma. Multiple myeloma may rarely present or evolve into a plasma cell leukemia, typically in far advanced disease. T cell malignancies that may present as chronic lymphoid leukemias, and in the past have often been referred to as T cell chronic lymphocytic leukemia, are large granular lymphocytic leukemia, adult T cell leukemia/lymphoma, Sézary cell leukemia and rare cases of non-Hodgkin's lymphoma that are T cell derived and may present or evolve into a leukemic phase. There is also a rare T cell counterpart of prolymphocytic leukemia. Distinguishing these diseases is critical for optimal care of these patients.
authors.affiliation: Lucille Parker Markey Cancer Center, Department of Internal Medicine, University of Kentucky Medical Center, Lexington 40536-0093, USA.
authors.forename: K A
authors.initials: KA
authors.lastname: Foon
mesh_terms: D015551:Autoimmunity; D001402:B-Lymphocytes; D002869:Chromosome Aberrations; D025063:Chromosome Disorders; D006801:Humans; D007943:Leukemia, Hairy Cell / Q000473:pathology / Q000503:physiopathology / Q000628:therapy*; D007945:Leukemia, Lymphoid / Q000473:pathology / Q000503:physiopathology* / Q000628:therapy*; D008223:Lymphoma / Q000503:physiopathology / Q000628:therapy*; D013601:T-Lymphocytes