Benign enlargement of the prostate gland
Benign prostatic enlargement occurs most often in men over the age of 60 years. Such enlargement is much less common in African and Asian individuals. It is unknown in eunuchs. The aetiology of the condition is unknown. Microscopically, hyperplasia affects the glandular and connective tissue elements of the prostate. Enlargement of the gland stretches and distorts the urethra, obstructing bladder outflow. The bladder musculature hypertrophies so that a higher than usual pressure is generated within the bladder in order to overcome the obstruction and allow voiding of urine. Bands of muscle fibre are seen at cystoscopy (trabeculation). Eventually the bladder becomes dilated and the muscle hypotonic. The sphincter mechanism at the vesicoureteric junction may be impaired and reflux of urine from the bladder into the ureters and upper urinary tract may occur.
Frequency of urination, usually first noted as nocturia, is a common early symptom. Difficulty or delay in initiating urination, with variability and reduced forcefulness of the urinary stream and post-void dribbling are often present. Suprapubic pain occurs if bladder bacteriuria is present, if a bladder calculus has formed as a result of stagnation of urine within the bladder, or in acute retention of urine. Flank pain may accompany dilatation of the upper tracts. Acute retention of urine (see below) or retention with overflow incontinence may occur. Occasionally, severe haematuria results from rupture of prostatic veins or as a consequence of bacteriuria or stone disease. Some patients present with severe renal failure. Abdominal examination for bladder enlargement together with examination of the rectum are essential. A benign prostate feels smooth. An accurate impression of prostatic size cannot be obtained on rectal examination.
This should include urine culture, assessment of renal function by measuring the serum urea and creatinine concentrations, measurement of prostate-specific antigen (markedly raised in prostatic cancer), a plain abdominal X-ray, and renal ultrasonography to define whether upper tract dilatation is present. Excretion urography is not usually necessary. The completeness of bladder emptying after an act of voiding can be assessed by ultrasonography or by inspection of the after-voiding radiograph carried out during excretion urography. Cystourethroscopy is essential.
MANAGEMENT AND PROGNOSIS
Patients with moderate prostatic symptoms can be treated medically. A number of drugs have been tried including a-blockers. Finasteride is a competitive inhibitor of Sa-reductase, which is the enzyme involved in the conversion of testosterone to dihydrotestosterone. This is the androgen primarily responsible for prostatic growth and enlargement. Finasteride decreases prostatic volume with an increase in urine flow. This new treatment must be compared with transurethral resection which is quick and safe.
Deterioration in renal function or the development of upper tract dilatation requires surgery. Transurethral resection is usually successful unless the gland is very large. It carries a lower morbidity and mortality with a shorter stay in hospital than open prostatectomy. Microwave hyperthermia, balloon dilatation and prostatic stents are all being tried, but long-term results are unavailable as yet. Very large glands require open transvesical prostatectomy.
In acute retention or retention with overflow, the first priorities are to relieve pain and to establish urethral catheter drainage. The bladder should be decompressed slowly to prevent bleeding from the mucosa. If urethral catheterization is impossible, suprapubic catheter drainage should be carried out. The choice of further management is then between immediate prostatectomy, a period of catheter drainage followed by prostatectomy, or the acceptance of a permanent indwelling suprapubic or urethral catheter.
Prostatic carcinoma Prostatic carcinoma accounts for 7% of all cancers in men and is the fourth commonest cause of death from malignant disease in men in England and Wales. Malignant change within the prostate becomes increasingly common with advancing age. By the age of 80 years, 80% of men have malignant foci within the gland, but most of these appear to lie dormant. Histologically, the tumour is an adenocarcinoma. Hormonal factors are thought to playa role in the aetiology.
Presentation is usually with symptoms of lower urinary tract obstruction or of metastatic spread, particularly to bone. The diagnosis may be made by the incidental finding of a hard irregular gland on rectal examination or as an unexpected histological result after prostatectomy for what was believed to be benign prostatic hypertrophy.
Investigation is as for benign enlargement of the prostate gland, with in addition measurement of prostate-specific antigen level, supplemented by transrectal ultrasound of the prostate and prostatic biopsy. A histological diagnosis is essential before treatment is considered. This may be obtained by:
CYTOLOGICAL STAINING of biopsy material from the prostate
HISTOLOGICAL EXAMINATION of biopsy material or material obtained at transurethral or open prostatectomy If metastases are present, serum acid phosphatase and serum prostate-specific antigen are usually elevated; it is a myth that elevated levels occur as a result of rectal examination.
Ultrasonography and transrectal ultrasonography are of value in defining the size of the gland and staging any tumour present. The upper renal tracts can be examined by ultrasonography for evidence of dilatation. Bone metastases may appear as osteosclerotic lesions on X-ray or may be detected by isotopic bone scans.
Microscopic, not clinically palpable turnour can be managed by watchful waiting. Treatment for disease confined to the gland is radical prostatectomy or radiotherapy, both resulting in an 80–90% 5-year survival. There have, however, been no controlled trials of this therapy and survival may be good without therapy. Locally extensive disease is managed with radiotherapy. Metastatic disease can be treated with orchidectomy, but many men refuse. Luteinizing hormone-releasing hormone (LHRH) analogues such as buserelin or goserelin are equally effective and preferred by many. The addition of an antiandrogen, e.g. cyproterone or flutarnide, seems to increase median survival. Non-hormonal chemotherapy is unhelpful.
The duration of survival depends on the age of the patient and the degree of differentiation and extent of the tumour.
A yearly rectal examination for men over 40 years of age remains a reasonable screening technique. Transrectal ultrasonography and measurement of serum prostatespecific antigen are being evaluated.
Testicular turnours, though uncommon, are the commonest malignant disease in men between the ages of 29 and 34 years All such turnours should nowadays be regarded as curable. Patient survival depends upon early diagnosis, accurate staging of the turnour and appropriate treatment and follow-up. The expertise of a specialist centre is invaluable.
More than 96% of testicular tumours arise from germ cells. Two main types of tumour exist: 1 Seminomas (about one-third) 2 Teratomas (about two-thirds)
The aetiology is unknown. The risk of malignant change is much greater in undescended testes and there is a history of orchidopexy in about 10% of patients.
Common presenting symptoms are:
• Testicular swelling, which may be painless or painful
• Symptoms from metastases
The differential diagnosis includes:
• Chronic infection, e.g. tuberculosis, syphilitic gumma
Diagnosis may only be possible after surgical explorationof the testis through the groin. Scrotal exploration and scrotal testicular biopsy should be avoided owing to the high incidence of tumour implantation. Staging of the tumour will require:
• Chest X-ray to look for metastases
• Estimation of o-fetoprotein and f3-human chorionic gonadotrophin concentrations (tumour markers)
• Abdominal CT scanning
Seminomas are radiosensitive, so turnours confined to the testis or with metastases below the diaphragm only are treated by radiotherapy. More widespread tumours require chemotherapy.
Teratomas are treated by orchidectomy if the growth is confined to the testis. Chemotherapy is required for more widespread disease.