title: Expanded populations of surface membrane immunoglobulin light chain-negative B cells in lymph nodes are not always indicative of B-cell lymphoma.
abstract: Immunophenotypic analysis is useful in distinguishing reactive from neoplastic lymphoproliferations, particularly when tissue is limited or histologic findings are equivocal. Surface membrane immunoglobulin (SmIg) light chain restriction in B cells is especially helpful in documenting clonality, and the loss of SmIg by B cells in extramedullary sites also has been used as a criterion to support the presence of lymphoma. However, we identified 3 cases of benign follicular hyperplasia (in 101 cases analyzed) with profound expansions (56%-88% of the B cells) of SmIg light chain-negative B cells without clonality by immunoglobulin heavy chain gene polymerase chain reaction. Thus, although uncommonly encountered, lack of SmIg light chain expression by B cells should not necessarily be interpreted as indicative of lymphoma. Interestingly, 2 of the 3 patients with these "aberrant" expansions were HIV+, and such patients are at heightened risk for the development of lymphoma. Therefore, there is the potential for misdiagnosing lymphoma if flow cytometric data are interpreted inappropriately in isolation.
authors.affiliation: Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA.
authors.forename: Xian-Feng
authors.initials: XF
authors.lastname: Zhao
authors.forename: Sindhu
authors.initials: S
authors.lastname: Cherian
authors.forename: Rachel
authors.initials: R
authors.lastname: Sargent
authors.forename: Raja
authors.initials: R
authors.lastname: Seethala
authors.forename: Hugh
authors.initials: H
authors.lastname: Bonner
authors.forename: Bernard
authors.initials: B
authors.lastname: Greenberg
authors.forename: Adam
authors.initials: A
authors.lastname: Bagg
mesh_terms: D000328:Adult; D001402:B-Lymphocytes / Q000276:immunology / Q000378:metabolism*; D002999:Clone Cells; D003937:Diagnosis, Differential; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D006965:Hyperplasia / Q000175:diagnosis* / Q000276:immunology; D007147:Immunoglobulin Light Chains / Q000276:immunology / Q000378:metabolism*; D016130:Immunophenotyping; D008198:Lymph Nodes / Q000166:cytology / Q000276:immunology / Q000473:pathology; D008206:Lymphatic Diseases / Q000175:diagnosis* / Q000276:immunology; D016393:Lymphoma, B-Cell / Q000175:diagnosis* / Q000276:immunology; D008297:Male; D016133:Polymerase Chain Reaction; D011947:Receptors, Antigen, B-Cell / Q000276:immunology / Q000378:metabolism*; D012189:Retrospective Studies
chemical_list: D007147:Immunoglobulin Light Chains; D011947:Receptors, Antigen, B-Cell