TLE1 [TLE1/2062]

Transducin-like enhancer of split 1 (TLE1) gene is a member of the TLE gene family and involved in control of hematopoiesis, neuronal, and terminal epithelial differentiation. By immunohistochemistry in formalin-fixed, paraffin-embedded tissues, TLE1 expression (nuclear staining) has been found in 35 of 35 molecularly confirmed synovial sarcoma cases, and was rare to absent in the 73 other soft tissue tumors examined (positive staining was found only in 1 of 43 malignant peripheral nerve sheath tumors and 1 pleomorphic sarcoma). Anti-TLE1 was more sensitive and specific for synovial sarcoma than other currently available immunohistochemical markers including BCL2, epithelial membrane antigen and cytokeratins, and had a positive predictive value of 92% and a negative predictive value of 100% in this clinical setting. TLE1 overexpression by immunohistochemistry is a highly sensitive and specific biomarker for the diagnosis of synovial sarcoma in the group of otherwise unclassifiable high-grade sarcomas.