Benign Prostatic Hyperplasia

Benign Prostatic Hyperplasia (BPH) is a non-malignant, age-related proliferation of the stromal and glandular elements of the prostate, arising in the transitional zone, that produces bladder outlet obstruction and lower urinary tract symptoms (LUTS) in ageing men. It is one of the most heavily tested urology topics in NEET PG, with crossover into pharmacology (alpha-blockers, 5-ARIs) and physiology (TUR syndrome).

Definition & basic concepts

BPH is a histological diagnosis (hyperplasia of epithelial and stromal cells), which is distinct from the clinical terms used in practice:

• BPH → histological proliferation (transitional zone).
• BPE (Benign Prostatic Enlargement) → the gland is enlarged on examination/imaging.
• BPO (Benign Prostatic Obstruction) → proven outflow obstruction (urodynamics).
• LUTS → the symptom complex; not synonymous with BPH (women and non-obstructed men also have LUTS).

High-yield: BPH is hyperplasia (increase in cell number), not hypertrophy. The name "prostatic hypertrophy" is a historical misnomer.

Anatomy of prostatic zones (McNeal)

The prostate is divided by McNeal into zones — a perennial single-best-answer favourite.

Zone	% of glandular tissue	Clinical significance
Transitional zone	~5–10%	Origin of BPH; surrounds proximal urethra
Central zone	~25%	Surrounds ejaculatory ducts; rarely diseased
Peripheral zone	~70%	Origin of ~70% of prostate cancer; palpable on DRE
Anterior fibromuscular stroma	—	Non-glandular; no disease origin

High-yield: BPH → transitional zone. Carcinoma prostate → peripheral zone. This single contrast is asked repeatedly.

The hyperplastic transitional zone compresses the peripheral zone into a "surgical capsule", and the median lobe enlargement can produce a ball-valve effect at the bladder neck causing severe obstruction with relatively small gland size.

Etiology & pathophysiology

BPH requires two prerequisites: ageing and functioning testes (dihydrotestosterone). Castrated males and those with congenital 5-alpha reductase deficiency do not develop BPH.

Hormonal basis:

• Testosterone is converted to dihydrotestosterone (DHT) by 5-alpha reductase type 2 (predominant in prostate stroma).
• DHT is ~10x more potent than testosterone at the androgen receptor and is the principal trophic hormone for prostatic growth.
• With age, oestrogen:androgen ratio rises, sensitising the gland to DHT and promoting stromal hyperplasia.

Two components of obstruction (the "two-pronged" model — basis of combination therapy):

1. Static component → mechanical bulk of enlarged glandular/stromal tissue (DHT-dependent → target of 5-ARIs).
2. Dynamic component → smooth-muscle tone of the prostate, bladder neck and capsule, mediated by alpha-1A adrenergic receptors (target of alpha-blockers).

High-yield: Alpha-1A receptor subtype predominates in the prostate and bladder neck — basis of "uroselective" alpha-blockers (tamsulosin, silodosin, alfuzosin).

Bladder response: Chronic obstruction → detrusor hypertrophy → trabeculation, sacculation, diverticula → later detrusor failure (decompensation) → chronic retention with overflow.

Clinical features (LUTS)

LUTS are classically divided into obstructive (voiding) and irritative (storage) groups:

Voiding (obstructive)	Storage (irritative)
Hesitancy	Frequency
Poor/weak stream	Urgency
Intermittency	Nocturia
Straining	Urge incontinence
Terminal dribbling	Dysuria
Incomplete emptying

A useful mnemonic for storage/irritative symptoms: "FUN" (Frequency, Urgency, Nocturia).

High-yield: Storage (irritative) symptoms are often the most bothersome to the patient and frequently persist or even worsen transiently after surgery.

Examination: Digital rectal examination (DRE) classically reveals a smooth, firm, rubbery, symmetrically enlarged gland with obliterated median sulcus and intact mucosa. (Contrast: hard, nodular, irregular gland with loss of mobility → suspect carcinoma.)

IPSS — symptom severity scoring

The International Prostate Symptom Score (IPSS) = the AUA Symptom Index plus one quality-of-life (QoL) question. It is the standard tool for grading symptom severity and monitoring response.

• 7 symptom questions, each scored 0–5 → total 0–35.
• Plus 1 QoL ("bother") question scored 0–6 (kept separate).

IPSS total	Severity
0–7	Mild
8–19	Moderate
20–35	Severe

High-yield: IPSS ranges — Mild 0–7, Moderate 8–19, Severe 20–35. The 7 symptom questions, 0–5 each, max 35. The QoL question is additional and not part of the 35.

Diagnosis & investigations

Initial (recommended) evaluation:

1. History + IPSS.
2. DRE (size, consistency, nodules).
3. Urinalysis (exclude infection, haematuria).
4. Serum PSA (and assess for cancer; also predicts gland volume/progression).
5. Serum creatinine / renal function (if obstruction/retention suspected).

Optional / confirmatory:

• Uroflowmetry — Qmax (peak flow rate) is the key value.
  • Qmax > 15 mL/s → unlikely obstruction.
  • Qmax < 10 mL/s → strongly suggests obstruction.
  • (A minimum voided volume of ≥150 mL is needed for a valid study.)
• Post-void residual (PVR) urine by ultrasound — elevated PVR (>50–100 mL) indicates incomplete emptying.
• Transrectal ultrasound (TRUS) — most accurate measure of prostate volume; guides biopsy and surgical planning.
• Pressure-flow urodynamics — gold standard to confirm bladder outlet obstruction (distinguishes obstruction from detrusor underactivity); reserved for equivocal cases.
• Cystoscopy — for haematuria, suspected stricture, or before surgery.

High-yield: Pressure-flow study is the investigation of choice to confirm true obstruction; uroflowmetry (Qmax) is the simplest screening tool.

PSA caveats: PSA rises with BPH, prostatitis, instrumentation, retention, DRE (mild) and cancer. 5-alpha reductase inhibitors halve serum PSA after ~6–12 months — so double the measured value when interpreting.

Management

Stepwise approach:

Watchful waiting (mild, IPSS ≤7, non-bothersome) → Medical therapy (moderate–severe) → Surgery (failed medical therapy or absolute indications).

Medical management

1. Alpha-1 adrenergic blockers — first-line, fastest symptom relief (act on dynamic component; work within days).

Drug	Selectivity	Key point
Tamsulosin, Silodosin	Alpha-1A selective ("uroselective")	Least hypotension; abnormal/retrograde ejaculation common (esp. silodosin)
Alfuzosin	Functionally uroselective	Favourable CV profile
Terazosin, Doxazosin	Non-selective alpha-1	Need dose titration; postural hypotension
Prazosin	Non-selective	Older; first-dose hypotension

High-yield: Alpha-blockers cause Intraoperative Floppy Iris Syndrome (IFIS) during cataract surgery (classically tamsulosin) — always elicit this history before ophthalmic surgery.

2. 5-alpha reductase inhibitors (5-ARIs) — act on the static component; shrink the gland (~20–25%) but take 3–6 months for effect. Most useful when prostate volume >40 mL or PSA elevated.

• Finasteride → inhibits type 2 only.
• Dutasteride → inhibits type 1 + type 2 (more complete DHT suppression).
• Adverse effects: decreased libido, erectile dysfunction, ejaculatory dysfunction, gynaecomastia; reduce risk of acute retention and need for surgery; halve PSA.

3. Combination (alpha-blocker + 5-ARI) — superior to monotherapy for large glands; the MTOPS and CombAT trials showed reduced long-term progression. (Memory: combination tackles both dynamic + static components.)

4. Anticholinergics / beta-3 agonists (mirabegron) — added for predominant storage symptoms when PVR is low (caution: anticholinergics may precipitate retention).

5. PDE-5 inhibitors (tadalafil 5 mg daily) — for LUTS with coexisting erectile dysfunction.

Phytotherapy (Serenoa repens/saw palmetto, Pygeum) — not proven superior to placebo in rigorous trials.

Surgical management

Absolute indications for surgery (mnemonic = "RUSHID" / the "complications of BPH"):

1. Refractory/recurrent urinary retention (failed trial without catheter).
2. Recurrent UTI secondary to obstruction.
3. Recurrent gross haematuria of prostatic origin.
4. Bladder stones (vesical calculi).
5. Renal insufficiency / hydronephrosis due to obstruction (back-pressure changes).
6. Large bladder diverticula.

High-yield: Recurrent retention, recurrent UTI, recurrent haematuria, bladder stones, renal impairment, and diverticula are the absolute indications — these mandate surgery regardless of IPSS.

TURP (Transurethral Resection of the Prostate) — the gold-standard surgical treatment for glands 30–80 g. Hyperplastic transitional-zone tissue is resected with a diathermy loop.

• Open prostatectomy (Millin's retropubic / transvesical) — reserved for very large glands (>80–100 g) or coexisting bladder diverticula/stones.
• TUIP (transurethral incision) — small glands (<30 g), preserves antegrade ejaculation; good in young men.

TURP complications

Complication	Notes
TUR syndrome	Dilutional hyponatraemia from absorption of irrigant
Retrograde ejaculation	Most common long-term sequela (~65–75%)
Bleeding/clot retention	Intra- and post-operative
Urethral stricture / bladder neck contracture	Late
Erectile dysfunction	~5–10%
Urinary incontinence	Sphincter injury (uncommon)
Recurrence	~10% need re-resection over years

High-yield: Retrograde ejaculation is the most common complication of TURP; TUR syndrome is the most dangerous immediate one.

TUR syndrome (must-know)

Caused by systemic absorption of hypo-osmolar, non-conductive irrigation fluid (classically 1.5% glycine; also sterile water, sorbitol-mannitol) through open prostatic venous sinuses during monopolar resection.

Pathophysiology flow: Open venous sinuses → absorption of glycine/water → dilutional hyponatraemia + hypo-osmolality + fluid overload → cerebral oedema. Glycine metabolism also yields ammonia (encephalopathy) and glycine itself causes transient visual disturbance/blindness.

Features: confusion, nausea/vomiting, bradycardia, hypertension then hypotension, visual disturbances, seizures, pulmonary oedema.

Risk factors: resection time >60 minutes, large gland, high irrigation pressure, opened sinuses.

Management: stop procedure, fluid restriction + IV furosemide, correct hyponatraemia with hypertonic (3%) saline if severe/symptomatic — slow correction to avoid central pontine myelinolysis.

High-yield: TUR syndrome = dilutional hyponatraemia with glycine irrigant. Use bipolar TURP with normal saline irrigation to virtually eliminate it.

Laser & newer procedures

• HoLEP (Holmium Laser Enucleation) — size-independent, "gold standard challenger," excellent haemostasis, suitable even on anticoagulants; low TUR-syndrome risk (saline irrigation).
• PVP / GreenLight (KTP) photoselective vaporisation — good for anticoagulated patients, less bleeding.
• Bipolar TURP — uses normal saline irrigation → no TUR syndrome.
• Minimally invasive: Prostatic Urethral Lift (UroLift), Rezūm (water-vapour thermal therapy), Aquablation — preserve ejaculatory function; for selected patients.

Complications of untreated BPH

• Acute urinary retention (AUR) — sudden painful inability to void; precipitated by alcohol, cold, anticholinergics, surgery.
• Chronic retention with overflow incontinence.
• Recurrent UTI; bladder calculi; bladder diverticula.
• Hydroureteronephrosis → post-obstructive renal failure (high-pressure chronic retention).
• Haematuria; detrusor decompensation.

Key differentials

Condition	Differentiating feature
Carcinoma prostate	Hard, nodular, irregular gland; high/rising PSA; peripheral zone; sclerotic bone mets
Prostatitis	Painful, boggy, tender gland; fever; pyuria
Urethral stricture	History of trauma/instrumentation/STI; cystoscopy shows narrowing
Neurogenic bladder	Neuro history (DM, cord lesion); urodynamics show detrusor dysfunction
Bladder cancer	Painless gross haematuria; smoking; seen on cystoscopy
Overactive bladder	Pure storage symptoms, no obstruction on flow study

Recently asked / exam angle

• Zone of origin — BPH (transitional) vs carcinoma (peripheral): a near-guaranteed one-liner.
• 5-alpha reductase: type 2 is prostatic; finasteride = type 2, dutasteride = types 1 & 2; 5-ARI halves PSA.
• TUR syndrome: irrigant = glycine 1.5%, mechanism = dilutional hyponatraemia, prevention = bipolar/saline, visual symptoms from glycine.
• IPSS cut-offs (0–7 / 8–19 / 20–35) and that it has 7 questions.
• Tamsulosin → IFIS (floppy iris) — frequently linked with ophthalmology.
• Absolute indications for surgery — picked as "which is an indication for TURP."
• Most common complication of TURP = retrograde ejaculation.
• Investigation of choice to confirm obstruction = pressure-flow urodynamics.
• HoLEP / GreenLight as preferred options in anticoagulated patients.
• Combination therapy rationale (static + dynamic; MTOPS/CombAT).

Rapid revision

1. BPH arises in the transitional zone; cancer in the peripheral zone.
2. BPH is hyperplasia, requires ageing + functioning testes (DHT).
3. DHT via 5-alpha reductase type 2 is the key growth hormone.
4. Alpha-1A blockers = fastest relief (dynamic); 5-ARIs = shrink gland (static, 3–6 months).
5. 5-ARIs halve PSA — double the value when interpreting.
6. Tamsulosin → IFIS in cataract surgery; silodosin → retrograde ejaculation.
7. IPSS: 7 questions, 0–5 each, max 35; Mild 0–7 / Moderate 8–19 / Severe 20–35.
8. Qmax <10 mL/s suggests obstruction; pressure-flow study confirms it.
9. TURP = gold standard for 30–80 g glands; open prostatectomy for >80–100 g.
10. TUR syndrome = dilutional hyponatraemia from glycine absorption; treat with fluid restriction ± 3% saline.
11. Bipolar TURP / HoLEP use normal saline → no TUR syndrome; HoLEP & GreenLight good for anticoagulated patients.
12. Absolute surgical indications: refractory retention, recurrent UTI, recurrent haematuria, bladder stones, renal failure, diverticula.