TY - JOUR TI - Clonal B-cell lymphocytosis exhibiting immunophenotypic features consistent with a marginal-zone origin: Is this a distinct entity? AU - Xochelli, A. AU - Kalpadakis, C. AU - Gardiner, A. AU - Baliakas, P. AU - Vassilakopoulos, T.P. AU - Mould, S. AU - Davis, Z. AU - Stalika, E. AU - Kanellis, G. AU - Angelopoulou, M.K. AU - McIver-Brown, N. AU - Ibbotson, R. AU - Sachanas, S. AU - Korkolopoulou, P. AU - Athanasiadou, A. AU - Anagnostopoulos, A. AU - Papadaki, H.A. AU - Papadaki, T. AU - Stamatopoulos, K. AU - Pangalis, G.A. AU - Oscier, D. JO - Blood advances PY - 2014 VL - 123 TODO - 8 SP - 1199-1206 PB - American Society of Hematology SN - null TODO - 10.1182/blood-2013-07-515155 TODO - CD5 antigen, adult; aged; article; bone marrow biopsy; cell infiltration; chromosome 7q; female; follow up; human; human tissue; immunogenetics; immunophenotyping; karyotype; major clinical study; male; marginal zone lymphoma; middle aged; monoclonal b cell lymphocytosis; priority journal; somatic hypermutation; splenomegaly; very elderly, Adult; Aged; Aged, 80 and over; B-Lymphocytes; Cell Lineage; Chromosome Banding; Clone Cells; Disease Progression; Female; Flow Cytometry; Follow-Up Studies; Gene Rearrangement, B-Lymphocyte, Heavy Chain; Humans; Immunophenotyping; Lymphocytosis; Lymphoma, B-Cell, Marginal Zone; Male; Middle Aged; Retrospective Studies TODO - The biological and clinical significance of a clonal B-cell lymphocytosis with an immunophenotype consistent with marginal-zone origin (CBL-MZ) is poorly understood. We retrospectively evaluated 102 such cases with no clinical evidence to suggest a concurrent MZ lymphoma. Immunophenotyping revealed a clonal B-cell population with Matutes score ≤2 in all cases; 19/102 were weakly CD5 positive and all 35 cases tested expressed CD49d. Bone marrow biopsy exhibited mostly mixed patterns of small B-lymphocytic infiltration. A total of 48/66 (72.7%) cases had an abnormal karyotype. Immunogenetics revealed overusage of the IGHV4-34 gene and somatic hypermutation in 71/79 (89.8%) IGHV-IGHD-IGHJ gene rearrangements. With a median follow-up of 5 years, 85 cases remain stable (group A), whereas 17 cases (group B) progressed, of whom 15 developed splenomegaly. The clonal B-cell count, degree of marrow infiltration, immunophenotypic, or immunogenetic findings at diagnosis did not distinguish between the 2 groups. However, deletions of chromosome 7q were confined to group A and complex karyotypes were more frequent in group B. Although CBL-MZ may antedate SMZL/SLLU, most cases remain stable over time. These cases, not readily classifiable within the World Heath Organization classification, raise the possibility that CBL-MZ should be considered as a new provisional entity within the spectrum of clonal MZ disorders. © 2014 by The American Society of Hematology. ER -