Prostatism: Signs
Having obtained the symptoms suggestive of outlet obstruction, the diagnosis should then be confirmed by the signs of outlet obstruction. On physical examination, the bladder may or may not be palpable. Rectal examination should normally reveal an enlarged prostate. However, it is the periurethral portion of the gland which initially enlarges; it is possible for this to cause very little overall enlargement of the gland. Usually, enlarged glands are more likely to be associated with obstruction, but it is possible to have
significant outlet obstruction in the presence of a relatively small gland palpable rectally. If the symptoms suggest prostation, the patient should be further investigated.
Urinalysis and urine culture should always be performed to rule out infection, diabetes and other renal and bladder problems which might contribute to the symptoms mentioned above.
Blood work should consist of indices of renal failure such as BUN and creatinine, plus serum acid and alkaline phosphatase. An elevated serum acid phosphatase in the absence of Paget’s disease or other problems associated with a tremendously high alkaline phosphatase suggests stage D carcinoma of the prostate, which may influence both investigation and treatment of the patient’s symptoms. However, the acid phosphatase is normally elevated only when the cancer has spread beyond the confines of the gland and only in a well differentiated tumor (a poorly differentiated cell cannot manufacture this complicated protein). An acid phosphatase is therefore not a screening test for prostatic carcinoma.
An IVP with a post-void film may be particularly useful. The pyelogram itself will show evidence of upper tract problems secondary to obstruction such as hydroureters and hydronephrosis. As well, an enlarged prostate can often be seen elevating the bladder base and even bulging into the bladder. The bladder film may also reveal evidence of cellules and diverticuli secondary to outlet obstruction and increased bladder pressures. The post-void film is most useful, however, in obtaining an assessment of residual urine without contaminating the bladder by instrumentation. On the other hand, one must keep in mind that elderly patients often find the hustle and bustle of a modern radiology department somewhat disconcerting and are not always able to relax enough to void properly. This can result in falsely increased residual urines, but a negative residual urine under these circumstances is most significant and suggests another cause for the patient’s symptoms.
If the above investigation suggests that the patient does suffer from prostatic hypertrophy or if the diagnosis is still somewhat confused, the patient should be referred for cystoscopy. This examination will not only assess the lower urinary tract, but will confirm whether or not the gland is obstructive. Also, examination of the bladder should show significant signs of obstruction, such as a high residual urine, trabeculation and cellule formation. This will be particularly useful information in the patient with a small gland but symptoms of obstruction. It may also be helpful in ruling out the patient with prostatitis who certainly would not benefit by surgery and might in fact be made worse. As mentioned earlier, the differentiation between true obstruction and prostatitis can be most difficult in the presence of an enlarged gland. Even at cystoscopy, the true nature of the problem may not be obvious and often on visualizing some obstruction and a little trabeculation the surgeon has been led into an operation which he subsequently regrets.