Aggressive B-cell lymphomas with translocations involving BCL6 and MYC have distinct clinical-pathologic characteristics.

OBJECTIVES Recently described, aggressive B-cell lymphomas with genetic abnormalities involving MYC and BCL2 have been shown to have a poor prognosis when treated with regimens for diffuse large B-cell lymphomas. Similar data on cases with concurrent MYC and BCL6 translocation are still scant. Moreover, little is known regarding the morphologic and immunophenotypic characteristics of these cases, which further complicates their identification. This study describes six cases of aggressive B-cell lymphoma with translocations involving MYC and BCL6. METHODS Six cases of large B-cell lymphoma with translocation involving MYC and BCL6 confirmed by fluorescence in situ were identified. The morphologic, immunophenotypic, and clinical features of the cases were examined. RESULTS All the patients were older women, and in 50% of cases, the presentation was extranodal. In two cases, the liver was involved at presentation. A starry-sky pattern was a constant feature of the cases in which the morphology could be reliably assessed. Five of six cases had an immunophenotype corresponding to the germinal center B cells, and only one was positive for BCL2, an immunophenotype reminiscent of that of Burkitt lymphoma. CONCLUSIONS B-cell lymphomas with translocations involving MYC and BCL6 have morphologic and immunophenotypic features suggestive of Burkitt lymphoma or gray zone lymphoma, and they tend to be diagnosed mainly in women, often in extranodal locations.