Burkitt lymphoma (BL) is a high grade BCL that is characteristically associated with the t(8;14)(q24;q32) translocation, involving the MYC gene on 8q24 and the IGH gene on 14q32 (illustrated in Figure 32-2e).30 Occasional BLs demonstrate variant t(2;8)(p11;q24) or t(8;22)(q24;q11) translocations involving MYC and the kappa and lambda light chain loci, respectively.31 These translocations result in increased expression of MYC activity and markedly increased cell proliferation. The site of translocation of MYC is reported to vary between sporadic and endemic BL; in endemic disease, the 8q24 breakpoint occurs up to 300 kb 5' from the coding region of the MYC gene, while sporadic BL characteristically involves a breakpoint in MYC exon 1.32 There also is variable involvement of the IGH gene, with endemic cases involving the J region, while sporadic cases involve the C regions. The degree of molecular variability in these translocations is the reason they are not amenable to detection by standard PCR assays. Routine karyotyping, Southern blot, and FISH analysis using MYC probes are successful in detecting almost all MYC translocations in BL.
Was this article helpful?