Variant t(2;11)(p11.2;q13) without IGK involvement in a case of mantle cell lymphoma.

Mantle cell lymphoma (MCL) is characterized by the t(11;14)(q13;q32) translocation, which leads to overexpression of the cyclin D1 (CCND1) gene. This translocation is observed in almost all cases of MCL. In this alteration, the involvement of immunoglobulin heavy chain (IGH) locus plays a key role in the activation of the CCND1 oncogene. Translocations affecting IGH loci are mostly prevalent in B-cell lymphomas, but variant translocations involving immunoglobulin kappa (IGK) or lambda (IGL) light chain loci have been observed in a minority of B-lymphoid malignancies. Variant translocations have been reported in only a few cases of MCL, however. This report presents a case of MCL with a variant t(2;11)(p11.2;q13), rearrangement of the CCND1 gene, and overexpression of cyclin D1. To characterize this rearrangement, specific noncommercial probes were used. This set of probes comprises IGK and REL flanking probes and 12 bacterial artificial chromosome (BAC) probes covering the region to be investigated. The results indicated that this alteration has not affected the IGK locus, and the breakpoint was within a 260-kb region located approximately 1 Mb telomerically to the IGK gene. It is probable that the KV3J gene localized in this region could deregulate the expression of cyclin D1.