MICROSATELLITE INSTABILITY IN FOLLICLE CENTER CELL LYMPHOMA

Fluorescent polymerase chain reaction (PCR) was used to assay 12 micro satellite markers (APC x 2, DCC, P53 x 2, RB1, NM23, WT1, D6S260, D6S2 62, D6S281 and TNFa) to look for evidence of microsatellite instabilit y in 40 cases of follicle centre cell lymphoma (FCC). Evidence of nove l alleles seen in the tumour tissue but not the normal uninvolved tiss ue was seen in seven cases (17%). In only two of these cases (5%) was more than one locus involved but in these cases multiple affected loci were seen (4/12 and 7/12 respectively). The detection of microsatelli te instability indicates a DNA repair defect such as that which would be predicted to occur in cells with mutated mismatch repair genes, a n ovel finding in FCC lymphoma.