In this unusual location, the detection of SYT-SSX fusion transcripts is a valuable diagnostic adjunct..     ///    SS is characterized by the chromosomal translocation t(X;18)(SYT-SSX) found in more than 95% of the tumors.     ///    We report a cooperative study from the French Sarcoma Group and the Mesopath Group on 40 t(X;18)(SYT-SSX)-positive primary intrathoracic SS. 