trisomy 3 occurs more frequently in T-cell lymphomas than in B-cell lymphomas

globally, 20-30% of T-NHL may carry trisomy 3, the highest incidence having been noted in lymphoepithelioid lymphoma, in low-grade peripheral T-cell lymphoma, in angioimmonoblastic lymphadenopathy and in adult T-cell leukemia-lymphoma

trisomy 3 is relatively rare in B-NHL, with the exception of marginal zone lymphomas (MZL) and mantle cell lymphoma (MCL); in MZL, total or partial trisomy 3 may occur in 50-70% of cytogenetically abnormal cases, with a reported incidence by interphase FISH in the 50-85% range; the incidence does not appear to vary according to the clinicopathologic features, with similar frequency in the extra-nodal MALT lymphoma, in the nodal and the splenic form of MZL; trisomy 3/3q was reported in 10-15% of MCL with an higher incidence (up to 40%) by molecular cytogenetic techniques; sporadically, other low-grade and high grade B-lymphoid tumors may carry trisomy 3/3q

the prognostic significance of trisomy 3 in T-cell and B-cell lymphomas is unknown; there does not appear to be a role for trisomy 3 in tumor progression from low-grade MALT lymphoma to the high grade form, whereas gains of 3q may be associated with the aggressive blastoid variant of MCL

trisomy 3 may be total or partial; commonly overrepresented segments in partial trisomy 3 include the q21-23 region and the q25-29 region; total/partial trisomy 3 may occur as an isolated anomaly in a minority of cases

the anomaly is readily detectable by G- and R-banding in most cases; however, FISH using a centromeric probe is more sensitive than conventional cytogenetics, allowing for the study of non-dividing cells and for the detection of partial trisomy in complex karyotypes with marker chromosomes