Lecture on Benign Prostatic Hyperplasia (BPH)

Introduction

• BPH: Non-cancerous growth of the prostate gland.
• Common in men over 50, considered a normal part of aging.
• Prostate Anatomy: Small gland under the bladder, in front of the rectum.
• Urethra and Prostate: Urethra passes through the prostate (prostatic urethra).

Prostate Anatomy and Zones

• Capsule: Tough connective tissue and smooth muscle.
• Peripheral Zone: Outermost, 70% glandular tissue.
• Central Zone: 25% glandular tissue, contains ejaculatory ducts.
• Transitional Zone: 5% glandular tissue, contains prostatic urethra.
• Microscopic Structure:
  • Basement membrane: Mainly collagen.
  • Basal cells: Cube-shaped.
  • Neuroendocrine cells: Scattered.
  • Luminal cells: Columnar, secrete alkaline prostatic fluid.

Prostate Function

• Prostatic Fluid: Nourishes sperm, slightly alkaline.
• Ejaculation Pathway: Sperm travels through vas deferens, ejaculatory ducts, and prostatic urethra.
• PSA (Prostate Specific Antigen): Liquefies semen post-ejaculation.
• Androgens: Testosterone and dihydrotestosterone (DHT), essential for prostate cell survival.
• 5α-reductase: Converts testosterone to DHT.

BPH Pathophysiology

• Aging: Decrease in testosterone, increase in 5α-reductase activity.
• DHT: Causes prostate cells to live longer and multiply.
• Prevalence: 50% of men by age 60, 90% by age 85.
• Non-Cancerous: No increased risk of prostate cancer.
• Symptoms: Urinary obstruction, bladder dilation, bladder hypertrophy, frequent infections.

Symptoms of BPH

• Urinary Issues: Weak stream, dribbling, dysuria, hesitancy, nocturia.
• Complications: Bladder dilation, hypertrophy, potential infections.

Diagnosis

• Digital Rectal Exam: Finger inserted into rectum to feel prostate.
• PSA Levels: Elevated due to increased prostate cells.

Treatment Options

• Medications:
  • 5α-reductase inhibitors (e.g., finasteride): Shrinks prostate by inhibiting DHT.
  • α1-antagonists (e.g., phenoxybenzamine): Relaxes muscles in bladder neck, prostate, urethra.
• Surgery: Transurethral resection of the prostate (TURP) to remove part/all of prostate.

Recap

• Cause: Increased 5α-reductase activity and DHT production.
• Symptoms: Urinary issues, bladder problems.
• Treatments: Medications, surgical procedures.