Clonality testing of malignant lymphomas with the BIOMED-2 primers in a large cohort of 1969 primary and consultant biopsies

• Published in: Pathology, research and practice research and practice, 2013-08, Vol.209 (8), p.495-502
• Main Authors: Hartmann, Sylvia, Helling, Alexandra, Döring, Claudia, Renné, Christoph, Hansmann, Martin-Leo
• Format: Article
• Language: English
• Subjects: Biopsy; Clonality; Clone Cells; Diagnosis, Differential; DNA Primers; Gene Rearrangement; Gene Rearrangement, gamma-Chain T-Cell Antigen Receptor; Genes, Immunoglobulin Heavy Chain; Genes, T-Cell Receptor gamma; Genetic Predisposition to Disease; Genetic Testing - methods; Hodgkin Disease - genetics; Hodgkin Disease - immunology; Hodgkin lymphoma; Humans; Lymphoma - classification; Lymphoma - genetics; Lymphoma - immunology; Lymphoma - pathology; Lymphoma, B-Cell - genetics; Lymphoma, B-Cell - immunology; Lymphoma, T-Cell - genetics; Lymphoma, T-Cell - immunology; Non-Hodgkin lymphoma; Phenotype; Polymerase Chain Reaction; Predictive Value of Tests; Reactive lesions; Referral and Consultation; Retrospective Studies
• ISSN: 0344-0338; 1618-0631
• DOI: 10.1016/j.prp.2013.05.004

The introduction of the BIOMED-2 primers allowed for reliable comparisons of clonality testing data of malignant lymphomas from different laboratories. This study undertook a retrospective analysis of a large cohort of cases; 1862 cases involved the immunoglobulin heavy chain locus (IGH VH–JH), and 1527 cases involved the T cell receptor gamma locus (TCRG). We confirmed previously published clonality rates in various B cell, T cell, and Hodgkin lymphoma cases. In reactive lesions, clonality for the IGH locus was frequently accompanied by additional polyclonal background. Clonality for TCRG was found in a subgroup of diffuse large B cell lymphomas. On closer morphologic inspection, seven cases appeared to have arisen from an underlying peripheral T-cell lymphoma. Five cases with monoclonal TCRG rearrangements, originally diagnosed as Hodgkin lymphomas, were reclassified as T-cell lymphomas. TCRG clonality was very rarely only observed in Hodgkin lymphoma. In case of clear TCRG clonality a T-cell neoplasia must be ruled out on morphological grounds. By careful examination of the rearrangement patterns, including an assessment of a co-amplified polyclonal background, clonality testing provides a powerful tool which in concert with morphologic and immunohistochemical parameters can lead to a firm diagnosis.