Array comparative genomic hybridization reveals a very high frequency of deletions of the long arm of chromosome 6 in testicular lymphoma.
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.
Bosga-Bouwer
Anneke G
AG
Department of Clinical Genetics, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands. a.g.bosga-bouwer@medgen.umcg.nl
Kok
Klaas
K
Booman
Marije
M
Boven
Ludolf
L
van der Vlies
Pieter
P
van den Berg
Anke
A
van den Berg
Eva
E
de Jong
Bauke
B
Poppema
Sibrand
S
Kluin
Philip
P
D002872:Chromosome Deletion; D002896:Chromosomes, Human, Pair 6 / Q000235:genetics*; D020732:Cytogenetic Analysis; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D016393:Lymphoma, B-Cell / Q000235:genetics*; D016403:Lymphoma, Large B-Cell, Diffuse / Q000235:genetics*; D008297:Male; D009693:Nucleic Acid Hybridization; D013736:Testicular Neoplasms / Q000235:genetics*