Gene rearrangement of bcl-1 and bcl-2 is confined to distinct subgroups of high-grade malignant B-cell lymphomas

The occurrence of bcl-1 and bcl-2 gene rearrangements was investigated in 37 cases of high-grade B-cell lymphomas. Bcl-2 rearrangement was detectable only in single cases of primary centroblastic lymphoma with a follicular growth pattern, whereas secondary centroblastic lymphomas evolving from a centroblastic–centrocytic lymphoma were positive in up to 60 per cent of the cases analysed. Bcl-1 rearrangement was found only in one case of immunoblastic B-cell lymphoma with a history of a pre-existing lymphoplasmacytoid immunocytoma. It is concluded that there may be a subgroup of centroblastic lymphomas with a biology similar to that of centroblastic–centrocytic lymphomas. The detection of bcl-1 rearrangement in high-grade lymphomas may indicate a secondary high-grade lymphoma.