Background and objectives: Diffuse large B-cell lymphomas (DLBCL) are common lymphomas that have been classified into three subgroups on the basis of their patterns of gene expression. The aim of this study was to characterize the clinical, biological, immunophenotypic and cytogenetic features of DLBCL with concurrent t(14;18) and 8q24/c-MYC rearrangement.
Design and methods: Sixteen cases of DLBCL with the dual translocation were identified between 1998 and January 2006. The clinical features of these cases were examined and morphological, immunohistochemical, flow cytometric and cytogenetic analyses were performed.
Results: All patients had aggressive features: B symptoms (81%), ECOG performance status >2 (81%), elevated lactate dehydrogenase (100%), stage IV disease (100%) with at least one extra-nodal localization (bone marrow, blood and central nervous system involvement in 93%, 50% and 50%, respectively) and age-adjusted IPI score of 3 in 81%. Despite intensive chemotherapy regimens (including allogeneic transplants), all patients died of disease progression. Progression-free and overall survival was 4 and 5 months, respectively. Immunophenotyping analysis (CD20, CD10, Bcl-6, Mum-1, Bcl-2 CD138, MIB1, CD19, CD5, CD38 and sIg) was performed and showed DLBCL with a germinal center (GC) profile. Ki-67 staining ranged from 70 to 90%. All cases assessed by cytogenetics analysis [conventional cytogenetic and/or fluorescence in situ hybridization (FISH)] had a complex karyotype. In one case, we identified a 8q24/c-MYC translocation variant never reported in DLBCL before: t(8;9)(q24;p13) and t(14;18)(q32;q21). The BCL-6 rearrangement was investigated by FISH and found to rearranged in four cases.
Interpretation and conclusions: In conclusion, DLBCL with concurrent t(14;18) and 8q24/c-MYC rearrangement is a subgroup of GC-DLBCLwith poor outcome. It is worth searching for the coexistence of dual translocations in Bcl-2-positive DLBCL with unusual aggressive presentation.