Two Burkitt's lymphomas with chromosome 6 long arm deletions.

Two new European Burkitt's lymphoma (BL) cases are reported. Their karyotypic abnormalities were unusual, without involvement of chromosomes #8, #14, #2, or #22. However, in both tumors, a 6q- chromosome was, present. These findings raise questions about the definition of BL and the involvement of various different DNA sequences in the mechanisms of BL genesis.