Benign Disorders of the Prostate

Prostate Gland

situated between urinary bladder and urogenital diaphragm; urethra runs through the middle of it

most prostate disorders produce secondary effects on the urinary tract

ejaculatory ducts (merged seminal vesicular ducts and vas deferens) pass through – merge with urethra at verumontanum

secretory products: probably serve several functions (under debate):

antibacterial – zinc

sperm transport – citrate

sperm protection – cholesterol/lipids

sperm liquefaction – plasminogen activator, seminin

with aging: Ý size, Ý risk of: benign prostatic hyperplasia, cancer, calculi, chronic bacterial prostatitis; ß production of prostatic antibacterial factor

Prostatic Calculi – deposits of mineral salts in prostatic acini and ducts; more common with increasing age

may be assymptomatic; possible focus for chronic prostatic infection; usually of little concern to urologists

Prostatitis – heterogeneous group of disorders

Acute Bacterial Prostatitis – age unspecific

Symptoms: acute chills, fever (flu-like symptoms); tender prostate on exam; irritated bladder, dysuria, etc.

Diagnosis: cultures of urine usually yield the bug (E. Coli, Klebsiella most common)

Treatment: easily treated with antibiotics

Chronic Bacterial Prostatitis – more common with advanced age; often associated urinary tract infection

Symptoms: generally wax and wane; no fever; dysuria common

Diagnosis: the bug can be isolated (usually E. Coli)

Treatment: responds well to antibiotics

Non-Bacterial Prostatitis/Prostodynia – etiology unknown; possibly related to "chemical excess" (alcohol, caffeine)

Symptoms: same as chronic bacterial; prostate and surrounding tissues are tender; may or may not be inflamed; dysuria

Diagnosis: by exclusion, since no bugs can be cultured

Treatment: poor response to antibiotics; possibly unculturable bug, or possibly autoimmune

accounts for 1/3 of pts that present with prostatitis - can’t treat because we don’t know what it is

Granulomatous Prostatitis: classic granulomatous appearance on histology (epitheloid histiocytes, giant cells, etc)

Nonspecific – most common; probably from stromal reaction to ductal obstruction, rupture and extravasation of contents

may mimic cancer on digital rectal exam

Infectious – rare; tuberculosis, fungi, parasites; can be easily diagnosed with special staining

Iatrogenic – due to surgical intervention (needle biopsy, prostate resection)

Systemic – very rare; Churg-Strauss vasculitis is an example

Benign Prostate Hyperplasia (BPH) – also known as adenofibromatous hyperplasia and glandular/stromal hyperplasia

may be stromal, glandular, or both; prostate can expand from its normal size (walnut) to the size of a grapefruit (rarely)

BPH primarily affects the prostate transition zone (peri-urethral); cancer primarily affects the peripheral zone

most frequent cause of urinary tract obstruction

Risk Factors: increased age (most men have a steadily increasing prostate size with normal androgen levels)

functioning testes and functioning prostate enzymes to convert testosterone Þ DHT

Etiology: Unknown

Pathophysiology: mesenchyme-derived stromal cells produce produce growth factors (TGF-b , EGF; unknown reason)

growth factors and androgen stimulate stromal and acinar (basal cell) proliferation Þ fibrostromal nodules

continued stromal and epithelial growth eventually leads to BPH

Clinical Presentation:

early problems are irritative: frequency, nocturia, urgency, incontinance

late problems are obstructive: weak stream, dribbling, hesitancy, straining, intermittency, incomplete voiding

continued obstruction: residual volume Þ infection; bladder hypertrophy Þ trabeculation Þ diverticuli; stones; hydronephrosis; ureteral dilation; renal damage (azotemia - Ý nitrogen in blood, renal failure)

Treatment: watchful waiting

surgery: TURP (transurethral resection); open prostatectomy; balloon dilation; hyperthermia; stints

medical therapy: 5a -reductase inhibitors (ß DHT); a -sympathomimetic drugs (ß bladder tone)