DETECTION OF CHROMOSOME-18 REARRANGEMENT IN SYNOVIAL SARCOMA BY FLUORESCENCE IN-SITU HYBRIDIZATION

Fluorescence in situ hybridization (FISH) evaluations of chromosome 18 were performed in synovial sarcoma, hemangiopericytoma, and mesotheli oma. Each case was evaluated with centromeric and whole chromosome pai nt probes. The synovial sarcomas had t(X;18) cytogenetically: but She FISH evaluator was blinded to the cytogenetic results and to the histo pathologic diagnosis. The FISH analyses were consistent with chromosom e 18 translocation in 6 of 7 synovial sarcomas, 0 of 3 hemangiopericyt omas, and 0 of I mesothelioma. These findings support the use of FISH in the diagnosis of synovial sarcoma.