Define Benign Prostatic Hyperplasia. Describe its pathophysiology, clinical features and complications.

The Concept

Benign prostatic hyperplasia (BPH) is a non-cancerous increase in the number of cells of the prostate — specifically the transitional (peri-urethral) zone. Because this zone surrounds the prostatic urethra, its enlargement compresses the urethra and obstructs the outflow of urine from the bladder, producing the lower urinary tract symptoms (LUTS) that define the disease. It is an almost universal consequence of ageing in men.

Pathophysiology

With increasing age, and under the influence of the androgen dihydrotestosterone (DHT — formed from testosterone by 5-alpha-reductase), the transitional zone undergoes hyperplasia. The enlarging gland compresses the prostatic urethra, so the bladder must generate higher pressures to void. The detrusor muscle initially hypertrophies and trabeculates to compensate, but may eventually decompensate, leading to incomplete emptying and retention.

Clinical Features — Luts

The symptoms divide neatly into two groups:

• Voiding (obstructive) symptoms — hesitancy, a poor or weak stream, straining, intermittency, terminal dribbling, and a sensation of incomplete emptying.
• Storage (irritative) symptoms — frequency, urgency, nocturia and urge incontinence (from the overactive, hypertrophied detrusor).

Examination & Complications

On digital rectal examination (DRE), BPH gives a smoothly enlarged, firm, rubbery prostate with a palpable median sulcus — in contrast to the hard, nodular, irregular gland with a lost sulcus of carcinoma. Complications of untreated obstruction are important: acute or chronic urinary retention, urinary tract infection, bladder stones, haematuria, overflow incontinence, and — in chronic retention — hydronephrosis and renal impairment.

Investigation & Management

Investigations include urinalysis, serum PSA (mildly raised; also helps exclude cancer), U&E/creatinine (renal function), ultrasound (post-void residual, hydronephrosis), uroflowmetry, and symptom scoring (IPSS). Management is stepwise:

• Watchful waiting for mild symptoms.
• Medical therapy — alpha-blockers (e.g. Tamsulosin) relax prostatic smooth muscle for rapid symptom relief, and 5-alpha-reductase inhibitors (e.g. Finasteride) shrink the gland over months; the two may be combined.
• Surgery — transurethral resection of the prostate (TURP) is the gold standard (open prostatectomy for very large glands), indicated for refractory symptoms or complications (retention, stones, recurrent UTI, renal impairment, recurrent haematuria).

BPH VS Prostate Cancer — the Key Contrast

A recurring exam theme is distinguishing BPH from prostate cancer, and the two differ in almost every respect. BPH affects the central transitional (peri-urethral) zone — which is why it causes obstruction early — whereas cancer arises in the peripheral zone and causes symptoms late. On DRE, BPH is smooth, rubbery and symmetrical with a preserved median sulcus, while cancer is hard, nodular, irregular with a lost sulcus. PSA is usually only mildly raised in BPH but can be markedly elevated in cancer. Keeping this contrast clear prevents mislabelling either condition.

Complications of TURP

Because TURP is the standard operation, its complications are examinable. Early problems include bleeding, clot retention and urinary infection; the classic (now rare) metabolic complication is 'TURP syndrome' — dilutional hyponatraemia from absorption of hypotonic irrigation fluid, causing confusion and cardiovascular upset. Longer-term effects include retrograde ejaculation (common), erectile dysfunction, urethral stricture, and incontinence. Modern bipolar and laser techniques reduce TURP syndrome. Awareness of these underlies proper consent.

A Note on Acute-on-chronic Retention

A common way BPH declares itself is with acute retention — sometimes precipitated by a urinary infection, constipation, alcohol, or drugs with anticholinergic effects. Some men have acute-on-chronic retention, where an already large, poorly-emptying bladder decompensates completely; these patients may have hydronephrosis and renal impairment, and after catheterisation show a large residual and a diuresis. Recognising that a man presenting in retention may have significant underlying obstruction and renal effects guides safe management and the timing of definitive treatment such as TURP.

• DRE: BPH = smooth, rubbery, enlarged, median sulcus present; cancer = hard, nodular, sulcus lost.
• Medical: alpha-blocker (tamsulosin — rapid) + 5-alpha-reductase inhibitor (finasteride — shrinks gland).
• Surgery: TURP (gold standard); indications = refractory symptoms, retention, stones, recurrent UTI/haematuria, renal impairment.

Transition zone enlarges in BPH; peripheral zone in carcinoma.

• BPH = benign hyperplasia of the transitional (peri-urethral) zone → urethral compression → bladder outflow obstruction (LUTS); driven by DHT with ageing.
• Voiding symptoms (hesitancy, poor stream, straining, dribbling, incomplete emptying) + storage symptoms (frequency, urgency, nocturia).
• DRE: smooth, rubbery, enlarged, median sulcus present (vs hard/nodular/lost sulcus in cancer).
• Complications: acute/chronic retention, UTI, bladder stones, haematuria, hydronephrosis/renal failure.
• Manage with alpha-blockers (tamsulosin) ± 5-ARI (finasteride); TURP is the surgical gold standard for refractory disease/complications.