PROSTATIC INTRAEPITHELIAL NEOPLASIA AND PROSTATE-SPECIFIC ANTIGEN

Prostatic intraepithelial neoplasia (PIN) is a putative premalignant l esion of the prostate gland. PIN has been demonstrated to share morpho logic and phenotypic similarities to invasive carcinoma of the prostat e. In addition, PIN is spatially related to invasive carcinoma and occ urs with greater frequency in men whose prostates harbor carcinoma. Pr ostate-specific antigen (PSA) is a glycoprotein produced by the prosta tic epithelium. For PSA to be detected in the serum, it must traverse several tissue layers to reach the circulatory system. PSA levels asso ciated with PIN are intermediate between those of benign and malignant prostate tissue. Spatially associated occult carcinoma, disruption of the basal cell layer, and increased vascularity may account for eleva ted PSA values in PIN.