COMBINATION OF T(14-18) AND A BURKITTS TYPE TRANSLOCATION IN B-CELL MALIGNANCIES

The combination of chromosomal translocations associated with bcl-2 re arrangement [t(14;18)] and c-myc rearrangement [t(8;14) t(8;22), or t( 2;8)] has infrequently been detected in lymphoproliferative disorders. We have recently identified four cases of a B-cell malignancy exhibit ing this dual translocation. In addition to t(14;18), one case had t(8 ;14) and three had the t(8;22). One case presented as de novo acute ly mphoblastic leukemia (ALL-L2), two as de novo high grade lymphomas and the fourth evolved to a 'blastic'' phase from a previously documented follicular lymphoma. Immunophenotyping and molecular analysis was per formed on three of the cases: all were negative for terminal deoxynucl eotidyl transferase (TdT) but were CD10 positive. Two of the three cas es with t(8;22) were negative for surface immunoglobulin (SIg) and pos itive for HLA-DR. Rearrangement of the oncogene bcl-2 was identified i n a single case by polymerase chain reaction (PCR) only. Similar to ca ses reported in the literature, all patients had a poor clinical outco me despite aggressive therapy. Dual translocation lymphoid malignancy has a relatively characteristic morphology and the diagnosis should be considered when there is a history of an antecedent low grade lymphom a or when there is discordance between the ''blastic'' morphology and the immunophenotype (TdT- and/or SIg +). Confirmation requires demonst ration of the characteristic translocations. Recognition of this entit y has significant clinical implications that may require consideration of alternate treatment strategies.