Prostate pathology: BPH, prostitis and prostate cancer (7.4)

Question 1

Describe the structure of the prostate gland

• Anatomical zones of the prostate
• Lobes of the prostate
• Epithelium in glands and ducts

Answer 1

Zones: Peripheral, anterior, central, transition

• Transition zone: Surrounds the urethra
• Central zone: Contains the ejeculatory ducts
• Peripheral zone: ‘Surrounds’ the central and transition zones
• Anterior zone: Anterior aspect of the prostate

Lobes: Median, anterior, posterior

• Median lobe: Most likely to undergo BPH
• Posterior lobe: DANGER ZONE. Most common site for prostatic cancer

Epithelium

• Gland: Columnar epithelium
• Duct: Cuboidal epithelium

Question 2

Explain the functions of the prostate gland

Answer 2

• Accessory sex gland
• A fibromuscular glandular tissue
• Adds nutrients and enzymes to the seminal fluid
  
  • PSA: A glycoprotein enzyme, liquefies semen allowing sperm to ‘swim’ easier
  • Prostaglandins: Dampen the immune response in the vagina and stimulate contraction of the vaginal (transport of sperm)
  • Fructose: Energy for spermatozoa
  • Zinc
  • Citrate: Provides optimal pH

Question 3

Benign Prostatic Hyperplasia (BPH)

Pathophysiology, clinical presentation, investigations and treatment

Answer 3

Pathophysiology: Proliferation of glandular and stromal elements - loss of balance between apoptotsis and proliferation, leading to enlargment of the prostate. Begins in the transitional and central zones (median lobe).

Androgen (testosterone) driven and related to oestrogen increase with age (from adipose tissue).

Clinical presentation: Dysuria, polyuria, post-voidal dribbling, pain in the lower back, haematuria, hesitancy, nocturia

• Failure to empty the bladder → urinary stasis → increased risk of infection
• Bladder distension can lead to kidney damage - hydronephrosis
• Urinary retention → Rupture/renal stones/kidney infection/incontinence/UTIs

Investigations:

• PSA: Raised, as secretory cells increase in number
• DRE: Prostate is enlarged with smooth nodules

Treatment:

• Alpha blockers (α1): Relaxes the smooth muscle wall of the urethra
  
  • Side effects include postural hypotension and retrograde ejaculation (internal urethral sphincter dysfunction)
• Alpha reductase inhibitors: Inhibits further testosterone mediated prostatic growth BUT can cause impotence
• Transurethral surgery: Removal of proliferative tissue constricting the urethra
  
  • RISKS AND COMPLICATIONS!!

Question 4

Prostatitis

Pathophysiology, clinical presentation, investigations and treatment

Answer 4

Pathophysiology: Acute inflammation of the prostate, commonly caused by E. coli. May be acute or chronic.

Can cause granulomatous inflammation.

Chronic - may have no obvious pathogen = chronic abacterial aprostitis.

Clinical presentation: Extremely painful, dysuria, polyuria, lower back pain

Investigations:

• DRE examination: Prostate is swollen enlarged and boggy

Treatment:

Question 5

Prostate Cancer

Pathophysiology, clinical presentation, investigations, metastasis sites and treatment

Answer 5

Pathophysiology: Adenocarcinoma, tending to begin in the peripheral zone.

Prostatic intraepithelial neoplasm → invasion of the basement membrane → local invasion → metastasis

Clinical presentation: No urinary symptoms for some time, as the enlargement occurs in the peripheral zone. Symptoms only begin to appear once invasive into central zone.

Urinary symptoms and back pain in later stages.

Investigations

DRE: Prostate is hard, fixed and ‘craggy’.

PSA: May increase is the tumour is well differentiated (retains function)

Transrectal ultrasound and biopsy: Complications include bleeding and septicaemia

• Grading: Gleason score generated. > number = worse prognosis
• Staging: Uses imaging.

Metastasis sites

Vertebral column = most common site of metastasis

Bone, vertebrae, ribs, long bones

Treatment

Conservative: Active monitoring

Radical: Surgery, radiotherapy and brachytherapy

• Consequences: Impotence, incontinence, stricture, death and failure

Palliative: Hormone differentiation, radiotherapy for metastasis, pain relief

Watchful waiting is often used as the adverse effects of treatment are so detrimental.

Question 6

LUT (lower urogenital tract) symptoms

Voiding and storage symptoms

Answer 6

LUTS very common in men > 60 y/o

Voiding: Hesitancy, poor stream and post-micturition dribble

• Linked to obstruction

Storage symptoms: Increased frequency, urgency, incontinence and nocturia

• Linked to bladder dysfunction

Question 7

Describe the value of PSA as a screening test for prostate cancer

Answer 7

PSA is not always elevated in cancer - it is only the case for well differentiated tumours (not undergone anaplasia).

PSA is good as a monitoring tool (to check treatment is working) but not as a screening tool.

Low sensitivity and specificity

> 10 PSA = Very likely to be cancer

• Criteria for screening?

Question 8

State the complications of transurethral surgery

Answer 8

• Bleeding
• UTI
• Incontinence
• Impotence
• Retrograde ejaculation
• Bladder neck stenosis

Question 9

Acute Urinary Retention

Presentation and treatment

Answer 9

Presentation: Very painful, palpable bladder, enlarged prostate on DRE

Treatment: Emergency catheterisation, treat any reversible factors (e.g. start alpha blockers), surgery

Question 10

Chronic Urinary Retention

Presentation, consequences, treatment

Answer 10

Presentation: Usually painless - despite huge palpable bladder, incomplete voiding, overflow in continence. May be associated with UTIs or bladder stones.

Consequences:

• Pressure is transmitted to the upper urinary tract ⇒ obstructive renal failure
• Bilateral hydroureteronephrosis
• Detrusor failure

Treatment: Surgery or long term catheter

Question 11

Outline the key symptoms experienced in the following conditions:

Prostatitis, BPH and prostate cancer

Answer 11