AR and prostate carcinoma: Hematoxylin-eosin (HE) and immunohistochemistry (IHC) revealed prostate carcinoma with negative staining of androgen receptor (AR) and strong expression of NE markers, including SYN, CgA, CD56 and INSM1 (Figure 2), indicating small cell neuroendocrine carcinoma (SCNEC) in 10 of 13 cores.