Saturday, November 21, 2009

Prostatic diseases

The two main disease of the prostate :

1) Benign prostatic hyperplasia (BPH)

In brief, what happens is as men ages (>45 yrs), testosterone levels are reduced and the levels can be relatively lower than the estrogen levels.
Hence, estrogenic effects over the prostate causes proliferation, first over the periurethral region.


Note that as the prostate enlarges, it compresses on and elongates the prostatic urethra. Hence, it results in symptoms of bladder outflow obstruction.
Initially, higher pressure is required to force the urine out of the bladder and as it becomes chronic, bladder muscular hypertrophy occurs.
Trabeculum formation occurs and as it saccules, bladder diverticulum forms.

 
 
These bladder diverticulum can result in 3 complications of urinary stasis :

Infection, Stones and Tumour

Eventually, these bladder diverticulum causes increased residual urinary volume and hence, back-pressure to the ureter and kidney occurs and hence resulting in hydroureter or even hydronephrosis.

What are the clinical features?

Symptoms usually becomes clinically apparent beyond 50 yrs of age.

1) Frequency

Patient noticed that there's increased frequency of micturition.
This is especially noticable when there's nocturia.

2) Urgency

Patient complains that he can no longer hold his desire to urinate.
There's an urgent need to pass urine once there's desire to urinate.
Sometimes can be associated with incontinence.

3) Hesitancy

Although there's intense desire to micturate, but the waiting time for the urine to start flowing out is delayed.
In other words, there's difficulty in initiating micturation.

4) Poor stream

Yes, there's a weak urinary stream.

5) Terminal dribbling

After cessation of the main stream, usually it ends with terminal dribbling.
As the patient loses his patience, the urine stains the underclothing.

6) Hematuria

Usually an initial or terminal hematuria

7) Uremia

Sometimes, patients can present with features of uremia.

On examination

Look for features of uraemia.
Bladder may be palpable when there's urinary retention.
Per rectal examination :

Remember to ask the patient to pass urine before examining the prostate.
The prostate is diffusely, however asymmetrically enlarged.
Surface, although smooth, can be bosselated since the enlargement is non-uniformed.
The consistency is usually rubbery, firm and homogenous.
Median sulcus of prostate is palpable, and the rectal mucosa overlying the gland is freely mobile.

2) CA prostate

Most common malignancy among men.
Age of presentation is usually around 80s-90s.
Basically, the symptoms are indistinguishable from BPH.
However, in addition to prostatism, other symptoms suggestive of CA prostate includes :

General debility (weight loss, malaise, body weakness, anorexia)
Bony pain (note that the metastatic deposits are osteosclerotic in nature, hence pathological fractures are actually uncommon)
As the tumour invades the adjacent structures, it may cause severe lower abdominal or perineal pain.

On examination -

Bony tenderness
PR examination reveals an asymmetrically enlarged gland, which is distorted and with a irregular, craggy surface.
The consistency is variable/knobbly, as some areas may be stony hard, others may be soft.
The median sulcus may not be palpable, and the rectal mucosa overlying the gland may be fixed.

Investigations

Any patient presents with BPH should be opted for CA prostate screening as well.

a) Full blood count and BUSE

FBC - to look for renal anemia
BUSE - evaluate renal function

b) Serum PSA

Serum PSA of >100ng/ml is significant for distant metastases.

c) Midstream urine collected for urine culture

To rule out urinary tract infections

d) Chest X-ray/X-ray of the spine

For any evidence of metastases


e) Urodynamic studies
f) If malignancy is suspected, prepare a transrectal ultrasonographic guided needle biopsy of the prostate.

Management

For BPH,

1) Symptommatic

If renal function is normal, and CA prostate has been ruled out, initial management should be medical.
For short-term relief of symptoms, start alpha-blockers (terazosin, tamsulosin)
Start finasteride therapy, which inhibits conversion of testosterone to dihydrotestosterone. Hence, this reduces the size of prostate gland.
It will require few months before this drugs start to exhibit it's effect.

2) Acute retention

If patient presents with acute urinary retention :

a) Admit the patient
b) Urinary catheterisation with strict asepsis
c) If not possible, start suprapubic aspiration using a wide cannula
d) Urinary catheter can be kept for 24-48 hrs at most. However, if the urinary symptoms are less, urinary catheter can be removed after 12 hrs. (Prescrbie alfuzosin 10mg/day after that)

3) Chronic retention

First, rule out malignancy and renal function impairment.
If there's renal function impairment leading to electrolyte imbalance (hyperkalemia, hypocalcemia, hyperphosphatemia), correct it first.
Then, only plan for prostectomy

For CA prostate,

1) For indicental focal findings of malignancy :

If the cells are well-differentiated -> wait-and-see
If cells are undifferentiated -> surgery + radiotherapy*

2) Localised malignancy without bony metastases :

Surgery + radiotherapy*

* : only for those with life-expectancy >10yrs

3) With bony metastases

Orchidectomy or start GnRH analogues

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