title: Clonal B-cell lymphocytosis exhibiting immunophenotypic features consistent with a marginal-zone origin: is this a distinct entity?
abstract: 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.
authors.affiliation: Hematology Department and HCT Unit, G. Papanicolaou Hospital, Thessaloniki, Greece;
authors.forename: Aliki
authors.initials: A
authors.lastname: Xochelli
authors.forename: Christina
authors.initials: C
authors.lastname: Kalpadakis
authors.forename: Anne
authors.initials: A
authors.lastname: Gardiner
authors.forename: Panagiotis
authors.initials: P
authors.lastname: Baliakas
authors.forename: Theodoros P
authors.initials: TP
authors.lastname: Vassilakopoulos
authors.forename: Sarah
authors.initials: S
authors.lastname: Mould
authors.forename: Zadie
authors.initials: Z
authors.lastname: Davis
authors.forename: Evangelia
authors.initials: E
authors.lastname: Stalika
authors.forename: George
authors.initials: G
authors.lastname: Kanellis
authors.forename: Maria K
authors.initials: MK
authors.lastname: Angelopoulou
authors.forename: Neil
authors.initials: N
authors.lastname: McIver-Brown
authors.forename: Rachel
authors.initials: R
authors.lastname: Ibbotson
authors.forename: Sotirios
authors.initials: S
authors.lastname: Sachanas
authors.forename: Penelope
authors.initials: P
authors.lastname: Korkolopoulou
authors.forename: Anastasia
authors.initials: A
authors.lastname: Athanasiadou
authors.forename: Achilles
authors.initials: A
authors.lastname: Anagnostopoulos
authors.forename: Helen A
authors.initials: HA
authors.lastname: Papadaki
authors.forename: Theodora
authors.initials: T
authors.lastname: Papadaki
authors.forename: Kostas
authors.initials: K
authors.lastname: Stamatopoulos
authors.forename: Gerassimos A
authors.initials: GA
authors.lastname: Pangalis
authors.forename: David
authors.initials: D
authors.lastname: Oscier
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001402:B-Lymphocytes / Q000473:pathology*; D019070:Cell Lineage / Q000235:genetics / Q000276:immunology*; D002871:Chromosome Banding; D002999:Clone Cells / Q000473:pathology; D018450:Disease Progression; D005260:Female; D005434:Flow Cytometry; D005500:Follow-Up Studies; D015326:Gene Rearrangement, B-Lymphocyte, Heavy Chain / Q000235:genetics / Q000276:immunology; D006801:Humans; D016130:Immunophenotyping; D008218:Lymphocytosis / Q000145:classification / Q000235:genetics / Q000473:pathology*; D018442:Lymphoma, B-Cell, Marginal Zone / Q000145:classification / Q000235:genetics / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies