Urethral metastasis from prostatic carcinoma as diagnosed by immunoperoxidase technique using prostate-specific antigen and prostate-specific acid phosphatase.

A rare case of urethral metastasis from prostatic adenocarcinoma is reported. Ordinary histological examination by hematoxylin and eosin staining could not determine whether the primary site was the prostate or the urethra. However, with an immunoperoxidase technique using prostate-specific acid phosphatase and prostate-specific antigen as markers for prostatic cells, we obtained a precise diagnosis of the primary sites. As a result, the patient could be successfully treated with hormonal therapy.