Genomic profiles of MALT lymphomas: variability across anatomical sites.

MALT lymphomas present common features, but important differences are associated with involvement of specific anatomical sites, many likely contributing to the biology. To test the existence of genetic alterations specific for primary anatomical sites of involvement, genomic profiles obtained with high-density arrays were analyzed in 130 MALT lymphomas across a spectrum of anatomic sites. Trisomies 3 and 18 and del(6q23) occurred at a similar frequency. Instead, gains at 6p appeared significantly more common among MALT lymphomas involving the orbital adnexa. Gastric involvement showed a trend for a higher frequency of 8q gains. In conclusion, MALT lymphomas appear to bear a common set of recurrent unbalanced genomic alterations independent of the anatomical site. This differs from what has been observed for common chromosome translocations. Only a few alterations such as gains at 6p and, possibly, gains at 8q show preferential involvement at specific anatomical sites.