t(18;22)(q21;q11) with rearrangement of BCL2 as a possible secondary change in a lymphocytic lymphoma

We report a lymphocytic lymphoma showing a combination of two characteristic neoplasia-associated chromosomal changes: trisomy 12, commonly observed in chronic lymphocytic leukemia and lymphocytic lymphoma, and t(18;22)(q21;q11), a variant form of the t(14;18)(q32;q21) found in most follicular lymphomas. Southern blot analysis was performed using probes for the 5' end of the BCL2 gene (18q21) and for the J lambda as well as C lambda immunoglobulin genes (22q11). With these two probes, a unique rearranged fragment was detected. Thus the t(18;22)(q21;q11) can be considered as a variant translocation of t(14;18)(q32;q21). The karyotypic analysis supports the assumption that in our case trisomy 12 occurred first, and t(18;22) appeared during tumor progression as part of the clonal evolution. This is at variance with the typical t(14;18), which has never been found to occur as a secondary change.