Presence of B‐cell clones in T‐cell lymphoma

The presence of B-cell clones in 76 cases with peripheral T-cell lymphoma (PTCL) and precursor T-lymphoblastic lymphoma (T-LBL) and its correlation with Epstein-Barr virus (EBV) was studied. DNA was extracted from paraffin sections and/or fresh-frozen samples and then used for clonality analysis using a modified BIOMED-2 polymerase chain reaction (PCR)-based method. T- and B-cell clones were detected in 59 (77.6%) and 14 (18.4%) of 76 patients, respectively: 90% and 30% of cases with PTCL, not otherwise specified, 76.4% and 17.6% of cases with angioimmunoblastic T-cell lymphoma, 77% and 7.6% of cases with adult T-cell lymphoma, 50% and 0% of cases with anaplastic large T-cell lymphoma, 62.5% and 12.5% of cases with T-LBL, and 50% and 0% of cases with intestinal T-cell lymphoma, respectively. Histological and immunohistochemical analyses revealed the presence of large B cells in lesional tissues, which were occasionally monoclonal. The presence of B-cell clones was highly associated with EBV positivity, as revealed by in situ hybridization. In two cases that were evaluated by serial histological and molecular examination, EBV-positive cells persisted in one and disappeared in the other. These findings suggest a role for EBV in the evolution of B-cell clones in T-cell lymphomas.