title: Biclonal chronic lymphocytic leukemia.
abstract: Chronic lymphocytic leukemia (CLL) is well characterized clinically and immunophenotypically. Demonstration of a monotypic CD19+, CD5+ B-cell population is central to the diagnosis. We report 2 cases of biclonal CLL. Two elderly men were encountered with an absolute lymphocytosis consisting of the typical CD5+, CD19+, CD23+ B-cell population seen in CLL; however, immunoglobulin light chain restriction by flow cytometry was not apparent as B cells expressed kappa or lambda light chains without a clear monotypic population. Molecular genetic analysis of flow cytometry-sorted cells (kappa and lambda populations) revealed in both cases 2 monoclonal B-cell populations. The characterization of these cases and a review of the issues surrounding biclonal CLL are presented.
authors.affiliation: Department of Clinical Pathology, Cleveland Clinic Foundation, OH 44195, USA.
authors.forename: E D
authors.initials: ED
authors.lastname: Hsi
authors.forename: G
authors.initials: G
authors.lastname: Hoeltge
authors.forename: R R
authors.initials: RR
authors.lastname: Tubbs
mesh_terms: D000368:Aged; D000944:Antigens, Differentiation, B-Lymphocyte / Q000032:analysis; D016175:B-Lymphocyte Subsets / Q000378:metabolism / Q000473:pathology; D015139:Blotting, Southern; D002999:Clone Cells; D004273:DNA, Neoplasm / Q000032:analysis; D005434:Flow Cytometry; D015326:Gene Rearrangement, B-Lymphocyte, Heavy Chain; D006801:Humans; D007147:Immunoglobulin Light Chains / Q000032:analysis; D007145:Immunoglobulin kappa-Chains / Q000378:metabolism; D007146:Immunoglobulin lambda-Chains / Q000378:metabolism; D016130:Immunophenotyping; D007621:Karyotyping; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D008297:Male; D016133:Polymerase Chain Reaction; D014407:Tumor Cells, Cultured
chemical_list: D000944:Antigens, Differentiation, B-Lymphocyte; D004273:DNA, Neoplasm; D007147:Immunoglobulin Light Chains; D007145:Immunoglobulin kappa-Chains; D007146:Immunoglobulin lambda-Chains