My Clinical Notes

• Also called nodular hyperplasia and is very common in men over 50
• Characterised by hyperplasia of prostatic stromal and epithelial cells resulting in large discrete nodules in the periurethral region of the prostate
• May compress the urethra causing partial or complete obstruction

 

Incidence

• 20% of men aged 40, 70% aged 60 and 90% aged 70
• Only 50% of those with microscopic evidence of nodular hyperplasia have any detectable enlargement of the prostate and only 50% of these individuals have any symptoms

 

Aetiology and pathogenesis

• Dihydrotestosterone (DHT), a metabolite of testosterone, is the ultimate mediator of prostatic growth
• It is synthesised in the prostate from testosterone by 5a-reductase type 2, which is localised principally in the stromal cells
• DHT has a mitogenic effect on epithelial and stromal cells
• DHT is 10 times more potent than testosterone as it dissociates more slowly from the androgen receptor
• Oestrogen also plays a role, possibly by rendering cells susceptible to the action of DHT
• There is also smooth muscle contraction of the prostate mediated by the a1-adrenergic receptor in the prostatic stroma
• Inhibitors of 5a-reductase decrease prostatic volume and urinary obstruction

 

Morphology

• Prostate can weigh 60-100g
• Nodules can be stromal or epithelial in origin
• The nodules may encroach on the urethra
• In some cases the nodular enlargement may project up into the floor of the urethra which is clinically termed ‘median lobe hypertrophy’
• Fibroepithelial nodules can contain glandular tissue from which may ooze white prostatic fluid
• BPH typically occurs in the transition zone of the prostate
• Can also contain foci of squamous metaplasia

 

Clinical course

• Symptoms relate to 2 effects;
  • Compression of the urethra with difficulty in urination
  • Urinary retention resulting in bladder hypertrophy, urinary infection, cystitis and renal infections
• In some cases sudden acute retention occurs which requires catheterisation
• The inability to empty the bladder completely resulting in increased susceptibility to infection
• Many secondary changes occur to the bladder;
• Hypertrophy
• Trabeculation
• Diverticulum formation
• Hydronephrosis, or acute rentention, with secondary urinary infection and azotemia and uraemia can develop
• Nodular hyperplasia is not considered to be a premalignant lesion
• Treatment is with a1 adrenergic blockage which relaxes the smooth muscle and inhibition of DHT

 

 

This entry was posted on Friday, December 21st, 2007 at 4:49 pm and is filed under Male genital tract. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.