Summary of chromosomal imbalances detected in 224 cases of untreated de novo DLBCL classified by gene-expression profiling. Red bars on the left side of the ideogram indicate losses of chromosomal material; green bars on the right side indicate gains of chromosomal material; thick green bars indicate chromosomal gains exceeding the cut-off value of 1.5 in a large chromosomal region; solid dots indicate high-level DNA amplifications. Each bar represents a chromosomal region gained or lost in a single sample. (A) GCB-DLBCL (n = 87); (B) ABC-DLBCL (n = 77); (C) PMBCL (n = 19); and (D) bar diagram indicating the frequencies of chromosomal imbalances that distinguish between ABC-DLBCL, GCB-DLBCL, and PMBCL (for statistical details see “Patients, materials, and methods”). All differences were statistically significant at P < .05, with the exception of 12q12 gains (P = .059).