Prostatic adenocarcinoma with marked neuroendocrine differentiation

A case is presented of prostatic cancer with marked neuroendocrine differentiation. Double-labeled immunohistochemical staining was performed with prostate-specific antigen and Chromogranin A. Both antibodies were localized to some of the cancer cells with Paneth cell-like features. Furthermore, most of the cancer cells were positively stained with luminal cell marker CAM 5.2, suggesting that neuroendocrine cells originated from the prostatic luminal cells.