Frequent occurrence of BCL6 rearrangements in nodular lymphocyte predominance Hodgkin lymphoma but not in classical Hodgkin lymphoma. Blood 101: 706–710

We studied the genomic status of BCL6 in 23 cases of nodular lymphocyte predomi-nance Hodgkin lymphoma (NLPHL) and 40 cases of classical Hodgkin lymphoma (cHL), using dual-color interphase fluores-cence in situ hybridization (FISH). The BCL6 rearrangement was identified in 48% of NLPHL cases and was not detected in cHL cases. As a confirmation, sequential or simultaneous immunohistochemistry (IHC) and FISH using CD20 or BCL6 anti-bodies and BCL6 DNA probes was per-formed in 8 NLPHL cases. The BCL6-associated translocations, t(3;22)(q27;q11), t(3;7)(q27;p12), and the most probable t(3; 9)(q27;p13), were identified in 3 cases. A consistent expression of BCL6 protein in popcorn cells with the highest number of intensely stained cells in cases with a genomic BCL6 rearrangement was shown by IHC. These findings support the hy-pothesis of a germinal center B cell– derived origin of NLPHL, indicate a signifi-cant role of BCL6 in the pathogenesis of NLPHL, and provide further evidence of the genetic diversity underlying the patho-genesis of NLPHL and cHL. (Blood. 2003