title: Prominent clonal B-cell populations identified by flow cytometry in histologically reactive lymphoid proliferations.
abstract: We describe 6 cases from the University of Washington Hematopathology Laboratory (Seattle) in which prominent, clonal, follicle center B-cell populations were identified by flow cytometry and confirmed by molecular methods, but in which the histologic features showed reactive follicular hyperplasia without evidence of bcl-2 overexpression or the t(14;18). The 6 cases included 5 lymph node biopsy specimens and 1 tonsillectomy specimen. Of the 6 cases, 5 occurred in young males (8-28 years) with no known immunologic abnormality; the other case was a 32-year-old, HIV-positive woman. In all 6 cases, clonal CD10+ B cells representing at least 20% of the total B cells were identified. Available clinical follow-up ranging from 13 to 56 months revealed no evidence of lymphoma in any of the 6 patients. Our findings add rare cases of follicular hyperplasia to the list of histologically reactive settings in which clonal B-cell populations might be present.
authors.affiliation: Department of Laboratory Medicine, University of Washington, Seattle, USA.
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Kussick
authors.forename: Michael
authors.initials: M
authors.lastname: Kalnoski
authors.forename: Rita M
authors.initials: RM
authors.lastname: Braziel
authors.forename: Brent L
authors.initials: BL
authors.lastname: Wood
mesh_terms: D000293:Adolescent; D000328:Adult; D001402:B-Lymphocytes / Q000276:immunology*; D015139:Blotting, Southern; D002648:Child; D002999:Clone Cells; D003937:Diagnosis, Differential; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D006965:Hyperplasia / Q000276:immunology* / Q000473:pathology; D007150:Immunohistochemistry; D008221:Lymphoid Tissue / Q000166:cytology* / Q000276:immunology / Q000378:metabolism; D008223:Lymphoma / Q000276:immunology / Q000473:pathology; D008297:Male; D015260:Neprilysin / Q000378:metabolism; D016133:Polymerase Chain Reaction; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism
chemical_list: D019253:Proto-Oncogene Proteins c-bcl-2; D015260:Neprilysin