Immunophenotypic Characterization of Benign and Malignant Prostatic Lesions

Biopsy diagnosis is the gold standard for differentiating benign and malignant prostatic enlargements. This study was aimed at supplementing biopsy diagnosis with immunophenotypic characters of prostatic lesions.

Twenty five cases each of nodular hyperplasia and adenocarcinoma prostate were compared for their morphologic appearances and immunophenotyping, by studying antibodies to prostate specific antigen (PSA), transglutaminase, chromogranin and high molecular weight keratin, proliferating cell nuclear antigen, cell death (apoptosis) and neovascularisation (CD 34).

Markers of differentiation (PSA and transglutaminase) aided recognition of higher-grade tumours. PSA negativity avoided metaplasia being overcalled as carcinoma. Loss of basal cells around malignant prostatic acini as determined by high molecular weight keratin (HMWK), was useful in foci of atypical small acinar proliferation and in prostatic intraepithelial neoplasia. Assessment of proliferation indices identified subsets of tumours, within conventional morphologic Gleason's grades, with a higher growth fraction. Cell death determination and study of tumour vessels did not offer any improvement on morphology.

Immunophenotypic assessment helps in refining morphologic diagnosis of prostatic lesions. Differentiation and proliferation markers objectively assess tumour characteristics with their biologic growth potential and are recommended for diagnostic use. They also help in assessement of response to therapy.