PSAP and carcinoma: Various immunohistochemical stains, including prostate-specific antigen (PSA), prostate specific acid phosphatase/prostatic acid phosphatase (PSAP/PAP), NKX3.1, P501S, prostate-specific membrane antigen (PSMA), androgen receptor (AR), and alpha methyacyl CoA racemase (AMACR), are available, which can help to differentiate prostatic adenocarcinoma from carcinomas from other organs.