A 58-year-old man presents to the emergency depament with severe back pain. His history is negative for trauma and he has no other complaints. He denies urinary frequency, hesitancy, or dysuria. A digital rectal examination confirms the presence of a firm, hard, asymmetrical and stony prostate, suggestive of prostatic malignancy. In addition to PSA, which of the following markers can be demonstrated in the tumour cells?

On immunohistochemistry, in addition to PSA, another useful marker is a-methylacyl coenzyme A racemase (AMACR), which is upregulated in prostate cancer. Most prostate cancers are positive for AMACR, the sensitivity varying among studies from 82% to 100%. Seminomas are positive for KIT, OCT-3/4, podoplanin. Embryonal carcinomas are also positive for OCT-3/4. The expression of AFP (alpha fetoprotein) is characteristic of yolk sac tumor cells; stains for cytokeratin are also positive.