Figure 2. Representative images of ERG, PTEN, and SPINK1 immunohistochemistry (IHC) and ETV1/4/5 RNA in situ hybridization (RISH).

ERG and PTEN immunostaining are shown from the same case, which expresses ERG (nuclear brown) and has lost PTEN expression in tumor cells, with retained expression in neighboring benign glands (denoted by a B). ETV1 and ETV4 RISH are from two representative positive cases (granular red staining) and are expressed in tumor glands, but not in intermingled benign glands (denoted by a B). ETV5 was negative in all cases. SPINK1 IHC is positive in a representative tumor case and negative in nearby benign glands (denoted by a B). Images at 200x magnification.