Clonal development of a blastoid mantle cell lymphoma studied with comparative genomic hybridization.

A molecular cytogenetic study was performed on the diagnostic tumor sample and three relapses from a case with blastoid mantle cell lymphoma. The clonal relatedness of the tumors was demonstrated by identical rearrangements of the immunoglobulin heavy chain gene and was supported by results from comparative genomic hybridization analyses. All samples shared the common alterations of losses of 6q, 9p, and 11q and gains of 3q, 9q, 12p, and 13q, suggesting that they were relatively early events in the tumorigenesis. Relapse 1 also showed a loss of 8p, while relapses 2 and 3 had gained the X chromosome and 7p, in addition, relapse 3 displayed gains of chromosomes 3 and 20. Taken together, the findings suggest that relapses 2 and 3 developed from the diagnostic tumor sample, while relapse 1 represents a separate lineage of tumor progression originating directly from a postulated ancestral tumor cell carrying the common chromosomal alterations identified in all tumors.