[Prostatic carcinoma: immunoperoxidase study with antisera against prostatic acid phosphatase and the...

An immunoperoxidase study in 19 patients with cancer of prostate, using antiserums directed against prostatic acid phosphatase (PAP) and prostate specific antigen (PSA), allowed classification of tumors as strongly, moderately and poorly differentiated, and undifferentiated forms. Tests were conducted on specimens fixed and embedded in paraffin wax. Evaluation of degree of positivity for cells most marked by PAP and by PSA failed to establish its correlation with tumoral differentiation. Results, in fact, showed that poorly differentiated or undifferentiated forms of prostatic carcinoma contained cells with enhanced positive reactions when compared with strongly differentiated forms. Morphologically strongly differentiated forms showed weaker positivity than observed in normal prostate, this positivity being relatively homogeneous throughout the zone of proliferation, and cells varied little in their degree of positivity. Characteristic findings in less well differentiated forms were several strongly positive cells, with marked differences in positivity between cells and frequent alternating positive and negative zones. These findings may be of particular interest for diagnostic interpretation of strongly or poorly differentiated forms.