title: CD5+ follicular lymphoma: a clinicopathologic study of three cases.
abstract: Follicular lymphoma (FL) is a low-grade lymphoma that typically lacks CD5 antigen expression. We report 3 cases of FL with unusual expression of CD5. All cases showed histologic features of FL, including effaced nodal architecture, follicular growth pattern, and a spectrum of grades from 1 to 3 using World Health Organization criteria. In flow cytometric studies, all 3 cases showed a light chain-restricted, CD19+, CD20+ B-cell population coexpressing CD10 and low-level CD5. Immunohistochemical studies demonstrated an identical B-cell immunophenotype with weak expression of CD5 and coexpression of bcl-2 protein and the germinal center-associated markers, CD10 and bcl-6 protein. None of the cases showed expression of CD43, cyclin D1, or IgD. By molecular analysis, immunoglobulin heavy chain gene rearrangements were demonstrated in all 3 cases, and 2 of 3 cases had a t(14;18). These cases highlight the difficulty classifying these lymphomas by flow cytometric studies alone and emphasize the importance of recognizing FL in the differential diagnosis of CD5+ B-cell lymphomas.
authors.affiliation: Laboratory of Pathology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.
authors.forename: Todd S
authors.initials: TS
authors.lastname: Barry
authors.forename: Elaine S
authors.initials: ES
authors.lastname: Jaffe
authors.forename: Douglas W
authors.initials: DW
authors.lastname: Kingma
authors.forename: Alvin W
authors.initials: AW
authors.lastname: Martin
authors.forename: Lynn
authors.initials: L
authors.lastname: Sorbara
authors.forename: Mark
authors.initials: M
authors.lastname: Raffeld
authors.forename: Stefania
authors.initials: S
authors.lastname: Pittaluga
mesh_terms: D000328:Adult; D001402:B-Lymphocytes / Q000378:metabolism / Q000473:pathology; D018956:CD5 Antigens / Q000378:metabolism*; D002883:Chromosomes, Human, Pair 14; D002887:Chromosomes, Human, Pair 18; D004273:DNA, Neoplasm / Q000032:analysis; D004268:DNA-Binding Proteins / Q000378:metabolism; D005260:Female; D005434:Flow Cytometry; D015326:Gene Rearrangement, B-Lymphocyte, Heavy Chain; D006801:Humans; D007147:Immunoglobulin Light Chains / Q000378:metabolism; D008224:Lymphoma, Follicular / Q000235:genetics / Q000378:metabolism* / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D015260:Neprilysin / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D051560:Proto-Oncogene Proteins c-bcl-6; D014157:Transcription Factors / Q000378:metabolism; D014178:Translocation, Genetic
chemical_list: D018956:CD5 Antigens; D004273:DNA, Neoplasm; D004268:DNA-Binding Proteins; D007147:Immunoglobulin Light Chains; D011518:Proto-Oncogene Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D051560:Proto-Oncogene Proteins c-bcl-6; D014157:Transcription Factors; D015260:Neprilysin