Chronic lymphoproliferative disorders.

There have been important advances in the diagnosis and treatment of chronic lymphoproliferative disorders. Three diseases stand out as examples of progress: chronic lymphocytic leukemia (CLL), hairy-cell leukemia (HCL), and adult T-cell leukemia-lymphoma. Improvements in diagnosis are the result of greater attention to cell morphology and the routine use of monoclonal antibodies, which in turn help define composite phenotypes that are specific for CLL and HCL. The combination of morphology and immunophenotype allowed the characterization of a new disorder, splenic lymphoma with villous lymphocytes, which was confused in the past with both CLL and HCL. The most important treatment developments stem from the availability of three nucleoside analogues: fludarabine, deoxycoformycin, and chlorodeoxyadenosine which, when used as single agents, are responsible for major improvements in remission rates in CLL (fludarabine, chlorodeoxyadenosine), HCL (deoxycoformycin, chlorodeoxyadenosine) and prolonged periods of disease-free survival. Adult T-cell leukemia-lymphoma remains a unique leukemia model, and interest in the worldwide distribution of the causative retrovirus, human T-cell lymphotropic virus I, continues with emphasis on epidemiologic and prevention studies.