Abstract
Despite the fact that numerous studies have been performed on diffuse large B‐cell lymphoma (DLBCL), only few have concerned extranodal lymphomas occurring in the testis. We performed a cytogenetic and molecular study of 17 testicular non‐Hodgkin lymphomas, of which 14 were proven primary DLBCL of the testis. Cytogenetic analysis revealed in 8 out of 11 evaluable cases a structural abnormality of the long arm of chromosome 6, with deletion or addition of material of unknown origin, and with breakpoints spanning the region 6q12‐6q23. The cytogenetic findings were confirmed by fluorescent in situ hybridization (FISH) with a chromosome 6 painting probe. Using array based‐comparative genomic hybridization on 16 evaluable cases, including 5 cases not tested by cytogenetics or FISH, 14 (88%) showed chromosome 6q deletions. We identified two regions of minimal deletion (RMD), at 104–113 Mb (6q16.3‐q21) and 137.5–138.8 Mb (6q23.3), respectively. In one case, we observed a 2.7 Mb homozygous deletion ranging from 135.3 to 138.0 Mb that partly overlapped with the RMD at 6q23.3. Our study indicates that 6q deletions play a major pathogenetic role in DLBCL of the testis and that many of these deletions are part of unbalanced translocations. © 2006 Wiley‐Liss, Inc.