title: Expression of bcl-6 and CD10 in primary mediastinal large B-cell lymphoma: evidence for derivation from germinal center B cells?
abstract: Primary mediastinal large B-cell lymphomas (LBCLs) constitute a unique subtype of diffuse LBCLs, with distinct clinical, immunophenotypic, and morphologic features. These lymphomas are thought to originate from the thymus, and it has been hypothesized that they derive from a population of B lymphocytes normally present in the thymic medulla. Most diffuse LBCLs harbor somatic mutations in their immunoglobulin genes, suggesting that they have been exposed to the germinal center. To investigate the possible relationship of mediastinal LBCLs to germinal center B cells, we analyzed the expression of bcl-6 and CD10 in 19 mediastinal LBCLs, using an immunoperoxidase technique on formalin-fixed tissue. We found that 19 of 19 (100%) mediastinal LBCLs were bcl-6+ and 6 of 19 (32%) mediastinal LBCLs were CD10+. Because mediastinal LBCLs usually lack BCL-6 gene rearrangement or mutations, expression of bcl-6 and CD10 in these tumors tends to support a germinal center derivation.
authors.affiliation: Department of Pathology, Massachusetts General Hospital, Boston 02114, USA.
authors.forename: L
authors.initials: L
authors.lastname: de Leval
authors.forename: J A
authors.initials: JA
authors.lastname: Ferry
authors.forename: B
authors.initials: B
authors.lastname: Falini
authors.forename: M
authors.initials: M
authors.lastname: Shipp
authors.forename: N L
authors.initials: NL
authors.lastname: Harris
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000378:metabolism*; D002452:Cell Count; D004268:DNA-Binding Proteins / Q000378:metabolism*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007124:Immunoenzyme Techniques; D016393:Lymphoma, B-Cell / Q000378:metabolism* / Q000473:pathology; D016403:Lymphoma, Large B-Cell, Diffuse / Q000378:metabolism* / Q000473:pathology; D008297:Male; D008479:Mediastinal Neoplasms / Q000378:metabolism* / Q000473:pathology; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000378:metabolism*; D009367:Neoplasm Staging; D015260:Neprilysin / Q000378:metabolism*; D011518:Proto-Oncogene Proteins / Q000378:metabolism*; D051560:Proto-Oncogene Proteins c-bcl-6; D013950:Thymus Gland / Q000378:metabolism / Q000473:pathology; D014157:Transcription Factors / Q000378:metabolism*
chemical_list: D014408:Biomarkers, Tumor; D004268:DNA-Binding Proteins; D009363:Neoplasm Proteins; D011518:Proto-Oncogene Proteins; D051560:Proto-Oncogene Proteins c-bcl-6; D014157:Transcription Factors; D015260:Neprilysin