Primary mediastinal (thymic) large B-cell lymphoma with a der(14)t(8;14)(q24;q32) and a translocation of MYC to the derivative chromosome 14 with a deleted IgH locus.

We report a case of primary mediastinal (thymic) large B-cell lymphoma (PMBL) with an initial karyotype containing numerical chromosomal aberrations: +X, +9, +12, +21, and a novel translocation t(2;11)(q?31; q23 approximately 24) with a duplication of the derivative chromosome 11. Subsequent multicolor fluorescence in situ hybridization (M-FISH) analysis revealed a der(14)t(8;14)(q24;q32). Further analysis using fluorescence in situ hybridization (FISH) with locus-specific probes revealed loss of the entire IgH locus from the der(14)t(8;14) and relocation of MYC to this derivative chromosome 14. Our data show definitively the existence of the t(8;14) in PMBL, previously only suspected. This finding supplies additional evidence that a translocation-mediated MYC activation may be an important event in the pathogenesis of this unique lymphoma.