Of 54 cases of prostatic small cell carcinoma, 26 (48%) were positive for TMPRSS2-ERG gene fusion by FISH and 12 (22%) showed overexpression of ERG protein by immunohistochemistry.    ///    "Of 54 cases of prostatic small cell carcinoma, 26 (48%) were positive for TMPRSS2-ERG gene fusion by FISH and 12 (22%) showed overexpression of ERG protein by immunohistochemistry. "    ///    We evaluated 54 cases of small cell carcinoma of the prostate and compared TMPRSS2-ERG gene fusion status by fluorescence in situ hybridization (FISH) to immunohistochemical staining with antibody to ERG.     ///    TMPRSS2-ERG gene fusion appears to be a highly specific alteration in prostatic carcinoma that is frequently shared by small cell carcinoma.     ///    Positive staining for ERG by immunohistochemistry is present in a subset of prostatic small cell carcinomas and correlates with the presence of TMPRSS2-ERG gene fusion.     ///    Frequent TMPRSS2-ERG rearrangement in prostatic small cell carcinoma detected by fluorescence in situ hybridization: the superiority of fluorescence in situ hybridization over ERG immunohistochemistry.. 