<prompt> 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?AMACRAFPPodoplaninOCT-34  <response>: 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-34, podoplanin. Embryonal carcinomas are also positive for OCT-34. The expression of AFP alpha fetoprotein is characteristic of yolk sac tumor cells; stains for cytokeratin are also positive. 