The literature review disclosed that, among six cases of de novo AML with t(11;20), the NUP98 gene was shown to be involved in one case and the NUP98/TOP1 chimera was detected in another.     ///    "In t-MDS cases, the translocation resulted in the NUP98/TOP1 fusion transcript. "    ///    "We report a further case of de novo AML, subtype M2 in the French-American-British (FAB) classification, in which the reverse-transcriptase polymerase chain reaction (RT-PCR) revealed the NUP98/TOP1 chimera and also, for the first time, its reciprocal TOP1/NUP98. "    ///    "The reciprocal TOP1/NUP98 chimera, however, has not yet been encountered. "