The response of poorly differentiated prostatic tumors to staining for prostate specific antigen and prostatic acid phosphatase: a comparative study.

A comparative study was done of the usefulness of immunohistochemical stains for prostate specific antigen and prostatic acid phosphatase in 20 poorly differentiated prostatic tumors. The stain for prostatic acid phosphatase was preferable to the prostate specific antigen stain not only because it was more intense and, therefore, more visible but also because it often was positive in areas in which an equivocal or negative stain was obtained with prostate specific antigen.