title: Differential diagnosis of L26-positive, CD15-negative Hodgkin's disease and large B-cell lymphoma with a high content of reactive T-cells: a morphologic and immunohistochemical study.
abstract: B-cell non-Hodgkin's lymphomas with a marked preponderance of reactive T cells, so-called T-cell rich B-cell lymphomas (TCRBCLs), can be morphologically confused with Hodgkin's disease (HD). To establish helpful distinguishing features in paraffin sections, 10 cases of L26-positive, CD15-negative HD and 10 cases of TCRBCL were compared; 4 cases of HD had morphologic features of the nodular lymphocyte predominant (LP) type. Nine of 10 cases of HD contained fewer than 20 mitoses/20 high power fields (hpf) and only 1 had pericapsular involvement. In contrast, 9 of 10 TCRBCL had greater than 20 mitoses/20 hpf and 7 had perinodal infiltration. HDLP was easily distinguished from TCRBCL by the expanded dendritic meshworks outlining the L & H nodules and the high content of CD57-positive lymphocytes. The remaining 6 cases of non-LP L26-positive HD had a relatively distinctive immunostaining pattern, with absence of CD45 and discordant reactivity for L26 and Ki-B5 in Reed-Sternberg cells and variants. Only 3 cases of TCRBCL had a similar CD45 and L26/Ki-B5 immunostaining pattern, and these could be distinguished by demonstrable cytoplasmic light-chain restriction. These results show that evaluation of the mitotic count, pericapsular involvement, and immunohistochemical staining patterns for Ki-M4p, CD57, L26/Ki-B5, and CD45 can help to discriminate TCRBCL from L26-positive HD when only fixed material is available.
authors.affiliation: Department of Pathology, University of Cologne, Germany.
authors.forename: D T
authors.initials: DT
authors.lastname: Nguyen
authors.forename: L W
authors.initials: LW
authors.lastname: Diamond
authors.forename: M L
authors.initials: ML
authors.lastname: Hansmann
authors.forename: R
authors.initials: R
authors.lastname: Fischer
mesh_terms: D000328:Adult; D000368:Aged; D000951:Antigens, Neoplasm / Q000276:immunology; D003937:Diagnosis, Differential; D005260:Female; D006689:Hodgkin Disease / Q000175:diagnosis* / Q000276:immunology / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D016256:Lewis X Antigen / Q000276:immunology*; D016393:Lymphoma, B-Cell / Q000175:diagnosis* / Q000276:immunology / Q000473:pathology; D008297:Male; D008875:Middle Aged; D013601:T-Lymphocytes / Q000276:immunology* / Q000473:pathology
chemical_list: D000951:Antigens, Neoplasm; D016256:Lewis X Antigen