Benign Prostatic Hyperplasia

Question 1

What is BPH?

Answer 1

gradual periurethral enlargement of the prostate

Question 2

What causes BPH?

Answer 2

• unclear
• major risk factor is aging (90% of men over 80 years), which may be related to age-related changes in androgen levels?
• genetic predisposition? race? diet?

Question 3

What is the pathology of BPH?

Answer 3

related to androgens (testosterone, DHT = dihydrotestosterone, estrogen)

normally:

• testosterone is converted to DHT and supports prostate growth and function
• 5 alpha-reductase supports the conversion of testosterone to DHT
• estrogen sensitizes prostatic cells to DHT
• as men age, testosterone levels, and thus DHT levels, decrease but estrogen changes very little
• the ratio of T:E is changed
• there is a relative increase (but not quantitative) in estrogen, causing more cells to be sensitized
• increase in sensitization causes enlargement
• hyperplasia of periurethral tissue compresses the urethra
• compression impedes urine flow
• urine accumulates in bladder

Question 4

When urine accumulates in the bladder, what changes occur?

Answer 4

• the bladder wall will thicken as a compensatory mechanism

- another compensatory mechanism to increase capacity is the formation of trabeculations and diverticula

Question 5

When urine accumulates in the bladder, what complications arise?

Answer 5

urine stasis, which can lead to 1) calculi and 2) infection

Question 6

When the bladder can no longer fill, what occurs?

Answer 6

• ureters fill with urine (hydroureter)
• distal ends of ureters fill and are weighed down, distend = fish hook ureter
• eventually, urine backs up all the way to the kidney causing hydronephrosis (distension of renal pelvis, calyxes)
• renal failure

Question 7

What are the manifestations of BPH?

Answer 7

• frequency (urinary bladder is full, causing frequent urge to void)
• hesitancy (difficulty starting flow)
• weak urine stream
• terminal or post-void dribbling

symptoms will incrementally increase

Question 8

How is BPH diagnosed?

Answer 8

• history, manifestations, presentation
• digital rectal exam
• PSA (prostate-specific antigen)
• – increase in total PSA is proportional to mass of the prostate, so an increase means an increase in prostate mass
• kidney function tests (BUN, creatinine)
• urinalysis (infection? calculi? hematuria?)

Question 9

How is BPH treated?

Answer 9

• may not need to treat if it isn’t severe
• prostectomy used to be the standard treatment
• drugs:
• – alpha adrenergic antagonists (acts on muscles to relax)
• – 5 alpha-reductase inhibitor if above doesn’t work, will decrease the DHT to stop progression
• – if severe both of above
• – surgery may be required (TURP, laser prostatectomy)