BCL-6 AND LYMPHOPROLIFERATIVE DISORDERS

We report a series of 37 cases of lymphoproliferative disorders with 3 q27 structural chromosomal abnormalities. Breakpoints at 3q27, the sit e of the bcl-6 gene, appear in a broad range of B cell lymphoma histol ogies but are most frequently detected in follicular lymphomas lacking a t(14;18) and diffuse large cell lymphomas. The majority of 3q27 rea rrangements result from translocations involving the immunoglobulin he avy or light chain genes, however, involvement of other partner chromo somes is also observed. Molecular rearrangement of bcl-6 is demonstrab le in a subset of cases. Bcl-6 is a recently identified gene encoding a zinc-finger protein. it is normally expressed in germinal center B c ells where it is believed to have a developmental or differentiation f unction. Transcriptional deregulation of bcl-6 through translocations, submicroscopic molecular rearrangements or point mutations may be res ponsible for this gene's putative lymphomagenic potential.