Secondary chromosomal aberrations were surveyed in non-Hodgkin's lymphomas (NHL) reported in the literature with one of the following, presently recognized, primary abnormalities: t(2;5), +3, t(3;14), del(6q), +X, and -Y. Of 2,175 NHLs with clonal karyotypic changes, 908 (42%) had one of the 13 selected primary chromosome rearrangements, and 670 (74%) of these lymphomas displayed additional abnormalities. The type and frequency of the secondary aberrations were ascertained and then correlated with both the type of primary abnormality and morphologic subtype; low-, intermediate, and high-grade according to the Working Formulation. The incidence of secondary aberrations differed not only among the primary abnormality subgroups, from 0% in del(11q) NHLs to 93% in t(3;14) lymphomas (P < .001) but also between B- and T-cell NHLs (78% versus 55%, P< .001) and among the different histologic subgroups: 66% in low-, 85% in intermediate-, and 71% in high-grade lymphomas (P < .001). The mean number of secondary changes per case also varied among the primary abnormalities, from none in del(11q) NHLs to 12.0 in inv(14) lymphomas (P < .001), and among the morphologic subtypes: 4.6 in low-, 6.7 in intermediate-, and 3.6 in high-grade NHL (P < .001). Recurrent secondary aberrations were found in 6 of the 13 primary abnormality subgroups: t(2;5), t(3;14), t(8;14), t(11;14), inv(14), and t(14;18). The most frequent secondary aberrations were +X, -Y, dup(1q), del(6q) varied both within and among the primary abnormalities; the most frequent imbalances were a gain of 1q23-31 and losses of 6q21, 6q23, and 6q25. Other common imbalances were deletions of 1p31-36, 1q31-44, 2q34-37, 7q35-36, 9p22-24, 11q23-25, 13q13-21, and duplication of 12q13-22. The distribution of the secondary changes was clearly nonrandom with the most common anomalies being -Y and +7 in t(2;5); +X, del(6q), and +7 in t(3;14); dup(1q) and +7 in t(8;14); -Y, del(6q), and -13 in t(11;14); del(6q), -17, and -18 in inv(14); and del(6q), +7, and +12 in t(14;18) NHLs. In general, the secondary aberrations were similar in lymphomas of different histologic subtypes but with the same primary abnormality, although some significant differences were discerned: +3, del(6q), +7, and +18 wee more common (P < .01) in intermediate-grade than in high-grade t(8;14) NHLs; monosomy 13 occurred only in intermediate-grade t(11;14) NHLs (P < .05); and +7 and t(8;14)/t(8;22) were more frequent (P < .01 and P< .001, respectively) in high-grade than in low- and intermediate-grade t(14;18) NHLs.(ABSTRACT TRUNCATED AT 400 WORDS)