[Analysis of SYT/SSX1 and SYT/SSX2 fusion genes from synovial sarcoma].

t(X;18)(p11;q11) translocation is the genetic aberration specific for synovial sarcomas. It results in fusion of SYT and an SSX gene leading to production of a chimeric protein SYT/SSX. The expression analysis of SYT/SSX1 and SYT/SSX2 chimeric transcripts was performed in formalin-fixed soft tissue tumor specimens, and the diagnostic significance of immunohistochemistry and FISH and RT-PCR methods was compared. Chimeric transcripts were detected in 12 of 16 synovial sarcomas: seven SYT/SSX1 and five SYT/SSX2 fusion variants; by fluorescence in situ hybridization (FISH), translocation was found in 13 of 16 sarcoma cases. Since synovial sarcoma represents a diagnostically challenging group, genetic analysis of translocations and chimeric transcripts is an extremely useful confirmatory diagnostic tool providing higher sensitivity than immunohistochemical markers.