BCL2 and BCL3 are recurrent translocation partners of the IGH locus

Chromosomal translocations affecting the immunoglobulin heavy chain (IGH) locus in chromosomal band 14q32 are the most frequent cytogenetic changes in B-cell lymphomas. We studied the presence of IGH translocations in a consecutively ascertained series of 94 classical Hodgkin lymphomas (cHL) by combined immunofluorescence for CD30 and interphase cytogenetics (FICTION technique). The Hodgkin and Reed–Sternberg cells of a total of 11 of 87 evaluable cases (13%) showed signal patterns indicative of IGH translocations. To identify the translocation partners, these cases were further studied with probes for the MYC, BCL2, BCL6, BCL3, REL/BCL11A, JAK2/PDCD1LG2 (alias PDL2) C14orf43, and C2TA loci. The IGH translocation partner could be identified in four cHL and involved BCL2 and BCL3 in two cases each. Immunohistochemistry in cases with suitable material revealed that tumor cells of the two cHL with IGH/BCL2 fusion and the cHL with IGH/BCL3 fusion expressed the BCL2 and BCL3 protein, respectively. These data indicate that BCL2 or BCL3 are recurrent translocation partners of the IGH locus in cHL; however, most of the translocation partners of IGH translocations in cHL remain to be identified.