Abstract
To the Editor: We performed a cytogenetic analysis in four cases of Ewing's tumor. All metaphases were obtained after two-day cultures of fresh tumor cells. RHG- and THA-banded chromosomes1 , 2 were analyzed, and the structural rearrangements were classified according to the international nomenclature.3 In all four cases clones with abnormalities were observed, and no cells with normal karyotype could be found. In all the cells, we observed reciprocal translocations involving band ql2 of chromosome 22 (Fig. 1): in Case 1, t(2;22;ll)(p22;ql2;?); in Case 2, t(9;22;20)(q34;ql2;pl2); in Case 3, t(l1;22)(q24;ql2); and in Case 4, t(ll;22)(q24;ql2) and t(l;22)(p21;ql2).Additional chromosomal abnormalities were observed . . .