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.
The high prevalence of the TMPRSS2-ERG gene fusion in prostatic small cell carcinoma as well as adenocarcinoma implies that small cell carcinoma may share a common pathogenic pathway with adenocarcinoma in the prostate.
ERG-TMPRSS2 rearrangement is shared by concurrent prostatic adenocarcinoma and prostatic small cell carcinoma and absent in small cell carcinoma of the urinary bladder: evidence supporting monoclonal origin.
Here, we used break-apart fluorescence in situ hybridization to assess TMPRSS2 and ETS aberrations in a series of select histologic variants: foamy gland carcinoma (N=17), ductal adenocarcinoma (N=18), mucinous carcinoma (N=18), and small cell carcinoma (N=7).