Immunohistochemical markers for prostatic cancer.

In a patient with an unclassifiable primary or metastatic neoplasm, with or without a history of prostatic cancer, immunostaining for PA or PSAP may prove invaluable. The procedure is simple, rapid, inexpensive, and extremely accurate in demonstrating the prostatic origin of tumors. It should be noted however, that the specificity of results is entirely dependent upon the specificity of the primary antibody, which should be meticulously defined before the procedure is used for diagnostic purposes.