The diagnosis of FS-DFSP was confirmed molecularly by the demonstration of a COL1A1-PDGFB fusion by fluorescence in situ hybridization and reverse transcription-polymerase chain reaction analyses.    ///    The diagnosis of FS-DFSP was confirmed molecularly by the demonstration of a COL1A1-PDGFB fusion by fluorescence in situ hybridization and reverse transcription-polymerase chain reaction analyses. 