Prostate Specific Antigen (PSA), a member of the human Kallikrein gene family, is a serine protease with chymotrypsin like activity, produced mainly by the epithelial cells that line the acini and duct of the prostate gland. Prostate specific antigen density (PSAD) calculation has been recommended as a more accurate and reliable method for differentiating benign and malignant lesions. Aims: The present study is undertaken to determine the PSA and PSAD levels in patients of BPH, PIN and carcinoma prostate, and to evaluate the diagnostic efficiency of PSAD in the management of carcinoma prostate and in differentiating patients of early prostate cancer (PIN) from those of BPH. Materials and Methods: The present study is a hospital based prospective study, undertaken in the department of pathology, Sri Siddhartha Medical College, Tumkur. This study was conducted on 90 transurethral resection of prostate (TURP) and prostate biopsy specimens obtained from patients presenting with complaints of enlargement of prostate in Department of Surgery, SSMC, Tumkur. Statistical Analysis Used: Data collected was entered in MS Excel spreadsheet and analysed using SPSS version 20. Results: In benign cases, SPSA was normal in 89.98% of cases. Modest elevation (4.1–10ng/ml) was seen is 10.71%
cases. In all the 84 cases, PSA density was within normal range (<0.15ng/ml/cc) and correlated well with the histological pattern.
In PIN cases, SPSA and PSAD were within normal range. All 5 malignant cases show SPSA values is significant zone (>10ng/ml) and PSAD in all the cases were above the cut-off value of 0.15ng/ml/cc.
Conclusion: PSAD offers a simple, readily acceptable, objective and economical approach to the detection of prostatic carcinoma. Further, immunohistochemistry and molecular genetic analysis are suggested.

Keywords: Prostate specific antigen (PSA); Prostatic carcinoma (PCa); Benign prostatic hypertrophy (BPH); Prostate specific antigen density (PSAD); Transurethral resection of prostate (TURP).