A novel five-way translocation, t(3;9;13;8;14)(q27;p13;q32;q24;q32), with concurrent MYC and BCL6 rearrangements in a primary bone marrow B-cell lymphoma

Abstract

Chromosomal translocations involving MYC at 8q24 are found in Burkitt lymphoma (BL), diffuse large B-cell lymphoma (DLBCL), and B-cell lymphoma, unclassifiable, with features intermediate between DLBCL and BL (BCLU). Here, we describe a novel five-way translocation, t(3;9;13;8;14)(q27;p13;q32;q24;q32), involving MYC, BCL6, and the immunoglobulin heavy locus (IGH@) in a 73-year-old man with BCLU. The bone marrow was massively infiltrated with 95.6% abnormal medium- to large-sized lymphoid cells without vacuoles. Flow cytometric analyses indicated that the infiltrating cells were positive for CD10, CD19, CD20, CD25, HLA-DR, and κ chain. Immunohistochemistry revealed that they were also positive for BCL2 and CD10, and weakly positive for BCL6. The MIB1 index was approximately 99%. G-banding and spectral karyotyping demonstrated the presence of a t(3;9;13;8;14)(q27;p13;q32;q24;q32). Fluorescence in situ hybridization detected an IGH/MYC fusion signal on the der(14)t(8;14)(q24;q32). In addition, 5' and 3'BCL6 signals were separated onto the der(9)t(3;9)(q27;p13) and the der(3)t(3;14)(q27;q32), respectively. Unexpectedly, no BCL6 signal was found on the non-translocated chromosome 3. Finally, the revised karyotype was as follows: 49,XY,del(3)(q27q27),t(3;9;13;8;14)(q27;p13;q32;q24;q32), +der(6)t(6;13)(q13;q32)t(9;13)(p13;q32),+7,+12,i(18)(q10)[2]/50,sl,+7[2]/50,sl,+2[1]. These results suggest that this five-way translocation could bring about the deregulated expression of MYC on the der(14)t(8;14) and BCL6 on the der(3)t(3;14) by the IGH@ enhancer/promoter in a single event and may have contributed to the development of this BCLU.