This is the typical clinical presentation of carcinoma of the prostate, which is probably the most frequent cancer in males (although lung cancer is the most frequent neoplastic cause of death). Autopsy studies show that small foci of adenocarcinoma are found in the prostate of up to 70% of men older than 80. Prostatic specific antigen (PSA) is expressed by both normal prostatic tissue and adenocarcinoma of the prostate. A rise in PSA plasma levels, therefore, simply results from any increase in the mass of prostatic tissue and cannot be used to differentiate between cancer and hyperplasia. Cancer arises more frequently in the peripheral zone of the gland, producing firm nodules on the posterior surface that can be detected on rectal examination. Metastasis to the bone can be osteoblastic (with formation of new bone) or osteolytic (with destruction of bone). Osteoblastic metastases in the veebral column are characteristic of prostatic adenocarcinoma. Chronic prostatitis presents with dysuria and perineal discomfo. The diagnosis relies on finding at least 10 leukocytes per high-power field on microscopic examination of expressed prostatic secretions. Chronic prostatitis is fuher classified into bacterial prostatitis if cultures are positive for bacteria, or abacterial prostatitis if cultures are negative. Increased plasma PSA is frequently seen. Multiple myeloma is a neoplasm of plasma cells that frequently manifests with osteolytic (not osteoblastic) lesions in the veebral column as well as other bones, such as the cranial vault and ribs. Prostatic hyperplasia is an extremely common disorder in middle-aged and elderly men. It involves the periurethral zone of the gland, leading to compression of the urethra, difficulty in urination, urinary retention, and recurrent cystitis. PSA levels are increased in a manner roughly propoional to the degree of prostatic enlargement. Ref: La Rochelle J., Shuch B., Belldegrun A. (2010). Chapter 40. Urology. In F.C. Brunicardi, D.K. Andersen, T.R. Billiar, D.L. Dunn, J.G. Hunter, J.B. Matthews, R.E. Pollock (Eds), Schwaz's Principles of Surgery, 9e.