title: Prolymphocytoid transformation of follicular lymphoma with coexpression of CD5 and CD10.
abstract: Histologic transformation of follicular lymphoma is usually to a diffuse large B-cell lymphoma. We present a rare example of a histologic transformation of follicular lymphoma manifested by prolymphocytoid morphology and an unusual immunophenotype characterized by coexpression of CD5 and CD10. The transformed prolymphocytoid lymphoma was positive for CD5 and CD10 antigens by both flow cytometry and immunohistochemistry. The case also expressed bcl-2 and bcl-6 proteins, and exhibited t(14;18), consistent with derivation from a pre-existing follicular lymphoma. Polymerase chain reaction analysis of the immunoglobulin kappa light chain genes derived from the follicular lymphoma and prolymphocytoid lymphoma showed identical rearranged bands, suggesting clonal identity of the two neoplasms. The basis for coexpression of CD5 and CD10 remains unclear. Because the preceding low-grade follicular lymphoma was positive only for CD10 and did not express CD5, CD5 expression appears to be an acquired phenomenon accompanying the process of histologic transformation in this particular case. Prolymphocytoid transformation, similar to other histologic forms of transformation of follicular lymphoma, appears to accompany clinical progression of disease.
authors.affiliation: Department of Pathology, City of Hope National Medical Center, Duarte, CA 91010, USA. slau@coh.org
authors.forename: Sean K
authors.initials: SK
authors.lastname: Lau
authors.forename: Lawrence M
authors.initials: LM
authors.lastname: Weiss
authors.forename: Yibin
authors.initials: Y
authors.lastname: Zhang
authors.forename: Qin
authors.initials: Q
authors.lastname: Huang
mesh_terms: D000328:Adult; D018956:CD5 Antigens / Q000096:biosynthesis* / Q000276:immunology; D002471:Cell Transformation, Neoplastic / Q000276:immunology / Q000473:pathology*; D018450:Disease Progression; D017809:Fatal Outcome; D005260:Female; D006801:Humans; D016130:Immunophenotyping; D015463:Leukemia, Prolymphocytic / Q000276:immunology / Q000473:pathology*; D008224:Lymphoma, Follicular / Q000276:immunology / Q000473:pathology* / Q000628:therapy; D016609:Neoplasms, Second Primary / Q000276:immunology / Q000473:pathology* / Q000628:therapy; D015260:Neprilysin / Q000096:biosynthesis* / Q000276:immunology; D012074:Remission Induction; D017211:Treatment Failure
chemical_list: D018956:CD5 Antigens; D015260:Neprilysin