“…1,2,8,9 Immunohistochemical analysis is useful, as seminal vesicle would show expression of high molecular weight cytokeratin in basal cells and would be negative for AMACR, in opposition to pros-tate adenocarcinoma. 10 Prostate-specific antigen and prostate-specific acid phosphatase are not useful for the differential diagnosis as they are not specific of prostate epithelium and may label seminal vesicle/ejaculatory duct tissue. 10 Prostate-specific antigen and prostate-specific acid phosphatase are not useful for the differential diagnosis as they are not specific of prostate epithelium and may label seminal vesicle/ejaculatory duct tissue.…”