Download Benign Prostatic Hyperplasia (BPH)

Benign Prostatic Hyperplasia
(BPH)
The prostate:
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Walnut-shaped gland surrounds the urethra.
Prostate weights about 20g.
Measures about 4 X3X2.
Apex = inferior portion of prostate.
Base = superior portion and continuous with
bladder neck.
Lobes of the Prostate
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Anterior lobe
Median lobe
Two lateral lobes
Posterior lobe
Image Source: SEER Training Website
* Histology of the prostate:
• The prostatic gland consists of glandular component
and fibromuscular stroma.
• The glandular component is formed of prostatic acini
arranged in lobules. The acini are highly folded and
lined by epithelial cells. The percentage of glandular
tissue vary between the different zones of the gland.
Prostate zones
* Central zone (CZ):
• Cone shaped region that surround the ejaculatory ducts
(extends from bladder base to the verumontanum)
• Accounts for 25% of glandular tissue.
* Peripheral zone (PZ):
• Posterolateral prostate
• Accounts for the majority of glandular tissue.
• The site of prostate adenocarcinoma
* Transitional zone (TZ):
• Surrounds the prostatic urethra proximal to the
verumontanum
• Accounts for only 5-10% of glandular tissue.
* Functions of the prostate:
n Secretes
prostatic
secretions.
n
During orgasm, prostate
muscles contract and
propel ejaculate out of the
penis
Benign prostatic hyperplasia
(BPH)
* Causes BPH:
n
n
n
BPH is part of the natural aging
process, like getting gray hair
or wearing glasses
BPH cannot be prevented
BPH can be treated
* Proposed Etiologies of BPH:
• The causes of benign prostatic hyperplasia are not fully
understood. Several theories have been proposed to explain
BPH, the most accepted one is hormonal changes.
- Estrogen: may play a role in BPH. As men age, testosterone
levels drop, and the proportion of estrogen increases, possibly
triggering prostate growth.
- In addition to the mechanical effects of the enlarged prostate,
clinical symptoms of lower urinary tract obstruction are also due
to smooth muscle-mediated contraction of the prostate. The
tension of prostate smooth muscle is mediated by the α1adrenoreceptor localized to the prostatic stroma.
* Morphological features of BPH:
* Gross Findings:
• The periurethral part of the gland is most commonly involved.
• Overall, the gland is enlarged, often reaching massive size, and
has a firm, rubbery consistency. Small nodules are present
throughout the gland, usually 0.5–1 cm in diameter but
sometimes much larger. Some of the larger nodules show
cystic change.
• The urethra appears slit-like and compressed.
* Microscopic Findings:
• The nodules are composed of a variable mixture of
hyperplastic glandular elements and hyperplastic
stromal muscle. The glands are larger than normal and
lined by tall epithelium that is frequently thrown into
papillary projections.
BPH
* Clinical Course:
• Symptoms of nodular hyperplasia, when present, relate to two
secondary effects:
1. Compression of the urethra with difficulty in urination.
2. Retention of urine in the bladder with subsequent distention and
hypertrophy of the bladder, infection of the urine, and
development of cystitis and renal infections.
* Symptoms:
Patients experience frequency, nocturia, difficulty in starting and
stopping the stream of urine, overflow dribbling, and dysuria
(painful micturition). In many cases, sudden, acute urinary
retention appears for unknown reasons and persists until the
patient receives emergency catheterization.
• In addition to these difficulties in urination, prostatic
enlargement results in the inability to empty the
bladder completely, so a considerable amount of
residual urine is left. This residual urine provides a
static fluid that is vulnerable to infection. On this
basis, catheterization or surgical manipulation
provides a real danger of the introduction of
organisms and the development of pyelonephritis.
• Many secondary changes occur in the bladder, such
as hypertrophy and diverticulum formation.
Hydronephrosis or acute retention, with secondary
urinary tract infection and even uremia, may develop.
• BPH is not considered to be a premalignant lesion.
* Treatment of BPH:
A. Mild cases:
• May be treated without medical or surgical therapy, by
decreasing fluid intake, especially prior to bedtime; moderating
the intake of alcohol and caffeine-containing products; and
following timed voiding schedules. The most commonly used
and effective medical therapy for symptoms relating to benign
hyperplasia are α-blockers, which decrease prostate smooth
muscle tone via inhibition of α1-adrenergic receptors.
B. Moderate to severe cases:
• With no response to medical therapy, a wide range of more
invasive procedures exists.
• Transurethral resection of the prostate (TURP). It is indicated
as a first line of therapy in certain circumstances, such as
recurrent urinary retention.
• Laser therapy.
TURP
(Transurethral resection of the prostate)
• Uses an electrical “knife” to surgically cut and
remove excess prostate tissue
• Effective in relieving symptoms and restoring
urine flow.
C. Open prostatectomy
• “Too large prostate” -- >100 gm
• Combined with bladder diverticulum or vesical
stone surgery
References:
Robbins and Cotran’s: Pathologic Basis of
Disease. Seventh edition.