Diagnostic Utility of TLE1 (Transducer-Like Enhancer of Split 1) in Distinguishing Synovial Sarcoma from Mimicking Tumors.

This study shows that TLE1 is a very sensitive and relatively specific IHC marker for SS. TLE1 expression can be observed in other soft tissue sarcomas but diffuse strong TLE1 expression is highly specific for SS. The diagnosis should not solely rely on TLE1 expression and morphologic features but should include soft tissue specific lineage markers to avoid misdiagnosis.