Prostate Anatomy: peripheral zone, central zone, and transition zone. Ejaculatory ducts empty into prostatic urethra at level of . Prostate composed of glandular epithelium contained within a fibromuscular stroma.
BPH = transition zone, usually begins in 5th decade of life. No causal assoc. between BPH and other dz’s ie. prostatitis or cancer. Obstructive symptoms see below. Gradual onset that may progress to urinary retention. See postvoid residual – abnormal amt. of urine in bladder after voiding. Indication for treatment is usually symptomatic relief, but could also be renal failure, recurrent bladder infections or stones. Medical tx. = alpha-1-adranergic blocking agents (ie. terazosin, doxazocin, and tamsulosin (flomax). 5-alpha-reductase inhibitor = Finasteride. Blocks conversion of testosterone to DHT, and will reduce the size of the prostate by 20-30%.
Surgical Tx for BPH = removal of obstructing prostate tissue by open or transurethral prostatectomy (TURP). Tx related impotence occurs in less than 5% of pts.
Acute Prostatitis – inflamed prostate, may be due to bacteria (most likely E. coli) or unknown etiology. Si/Sx – fever, back pain, chills, and dysuria, with swollen prostate, boggy to touch, very tender, poss inc. WBC. Non-bacterial prostatitis is symptomatically indistinguishable from bacterial, Chlamydia trachomatis may be cause in some cases.
Prostodynia – aching perineal discomfort, urinary frequency, urgency, and dysuria. Obstructive symptoms = urinary hesitancy, dribbling, and difficulty emptying the bladder.
Malignant Diseases of the Prostate: Carcinoma of the prostate is #1 cancer of men and 2nd leading cause of cancer death in U.S. 95% are adenocarcinoma arising from acinar structures. Higher incidence in African American men than caucasions. Early obstructive symptoms may be present and increase as the cancer grows. Late sx’s include pelvic pain, ureteral obstruction, or bone pain from distant mets. Screening (digital rectal exam and PSA) should start at 50 yrs, and 40 yrs for those with increased risk ie. fam hx or AA’s. Most cancers arise in the peripheral zone, and on DRE the prostate may have an area of induration or nodularity.
PSA – serine protease enzyme, responsible for cleaving proteins in post-ejaculatory semen. Secreted by both benign and malignant protatic epithelial cells. Elevated in men with prostatitis, BPH, or prostate cancer. Level of 4.0 ng/ml is normal, and a change of .75 ng/ml/yr is acceptable. Two forms of PSA exist, unconjugated and free, an increased ratio of free:unconjugated is seen in BPH.
Transrectal Ultrasonagrophy (TRUS) – best imaging test for the prostate, but not for prostate screening.
Tumor Grade – uses the Gleason score. Tumors with scores of 2 – 4 are well-differentiated, 5 -7 moderately differentiated, 8 -10 poorly differentiated.
Tumor Staging – T0 = no evidence of primary tumor, T1 = clinically inapparent tumor, T2 = tumor confined within prostate, T3 = tumor extends through the prostate capsule, T4 = tumor is fixed or invades adjacent structures. If metastasis is suspected or PSA > 10/Gleason score > 7, then bone scan and lymph node dissection are performed.