BCL6-translocations affect the phenotype of follicular lymphomas only in the absence of t(14;18)IgH/BCL2.

BACKGROUND: The translocation t(14;18)IgH/BCL2 is the molecular hallmark of follicular lymphomas (FL). A subset of cases harbours translocations involving the BCL6-gene locus. This study aimed to determine the frequency of BCL2- and BCL6-translocations in FL and to identify morphological and immuno-histochemical features with respect to the presence of BCL2- and BCL6-translocations.

MATERIALS AND METHODS: Fluorescence-in-situ-hybridisation (FISH) was used to determine the BCL2- and BCL6-translocation status of 102 FL and these were compared to morphological and immunohistochemical parameters.

RESULTS: Lymphomas with BCL6- and BCL2-translocations were very similar to t(14;18)-positive lymphomas without BCL6-translocations. In contrast, t(14;18)-negative lymphomas with BCL6-translocations were amongst others of higher grade, less often CD10-positive, involved the bone marrow less frequently and did not infiltrate the lymph node capsule.

CONCLUSION: BCL2- and BCL6-translocations correlate with particular phenotypes of follicular lymphomas. BCL6-translocations seem to affect the phenotype only when they are not accompanied by BCL2-translocations.