URINARY SYSTEM WORKSHOP
CASE 2
A 78 year-old man was referred to an urologist because of the following urinary
symptoms. He complained of hesitancy, weak stream (often intermittent) and straining to
pass urine. He also had urgency, frequency and nocturia.
On rectal examination an enlarged, firm and nodular prostate was palpated. Urodynamics
confirmed obstruction to urine flow and a significant degree of residual urine in the
bladder following micturition.
The following tests were ordered – urine to be sent to the microbiological laboratory;
blood for a full blood count; electrolytes; urea; creatinine; and prostate specific antigen
(PSA). All were reported as normal.
Question 1
What is the likely diagnosis?
Answer:
Question 2
What is the rationale for ordering the tests listed above?
Answer:
Because the patient’s symptoms placed him at the severe end of the International Prostate
Symptoms score, it was decided to treat him surgically rather than by medication. A
transurethral resection of the prostate (TURP) was performed.
Question 3
What changes occur in the bladder secondary to long-standing obstruction?
Answer:
Question 4
List some other causes of bladder outlet obstruction
Answer
Question 5
If bladder outlet obstruction is not relieved and hydronephrosis results, what further
complications may ensue?
Answer:
The histopathologist reported the TURP specimen as showing benign prostate
hyperplasia but in addition, about 5% of the sections showed the presence of a welldifferentiated prostatic adenocarcinoma.
Question 6
What is the significance of this and what is the subsequent management?
Answer:
Question 7
In the case of a primary diagnosis of carcinoma of the prostate:a) What are the gross and microscopic findings in contrast to benign hyperplasia?
b) What two factors are the best indicators of prognosis?
c) How and where would you look for evidence of spread of the carcinoma?
Answer:
Answer 1
Benign prostatic hyperplasia (BPH) leading to urethral compression and urinary
obstruction.
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Answer 2
Urine – to exclude a urinary infection to which patients with obstructive uropathy are
prone. The residual urine in the bladder is liable to become infected. E.coli is the most
common organism isolated.
Blood – FBC as a routine, especially if surgery is being contemplated. Electrolytes, urea
and creatinine to assess renal function. Unrelieved obstruction may result in hydroureter
and hydronephrosis and renal impairment. Imaging would be used to detect this if
suspected.
PSA – this can be raised particularly in prostatic carcinoma but also in other conditions
such as prostatitis or even simply following palpation of the prostate. The upper limit of
normal is 4 ng/l.
A normal prostate gland is about 3 to 4 cm in diameter. This prostate is
enlarged due to prostatic hyperplasia, which appears nodular. Thus, this
condition is termed either BPH (benign prostatic hyperplasia) or nodular
prostatic hyperplasia.
A frequently performed operation for symptomatic nodular prostatic
hyperplasia is a transurethral resection, which yields the small "chips" of
rubbery prostatic tissue seen here.
Microscopically, benign prostatic hyperplasia can involve both glands and
stroma, though the former is usually more prominent. Here, a large
hyperplastic nodule of glands is seen.
At higher magnification, the enlarged prostate has glandular hyperplasia.
The glands are well-differentiated and still have some intervening stroma.
The small laminated pink concretions within the glandular lumens are known
as corpora amylacea.
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Answer 3
Hypertrophy of the muscle, increased trabeculation and diverticula. The latter are prone
to become infected. Bladder calculi may form if the obstruction is not relieved.
The enlarged prostate gland seen here not only has enlarged lateral lobes,
but also a greatly enlarged median lobe that obstructs the prostatic urethra.
This led to obstruction with bladder hypertrophy, as evidenced by the
prominent trabeculation of the bladder wall seen here from the mucosal
surface. Obstruction with stasis also led to the formation of the yellow-brown
calculus (stone).
Obstruction from nodular prostatic hyperplasia has led to prominent
trabeculation seen on the mucosal surface of this bladder with hypertrophy.
The stasis from obstruction predisposes to infection. The obstruction can
also lead to bilateral hydroureter and hydronephrosis.
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Answer 4
Malignant causes – prostatic adenocarcinoma, strategically located bladder carcinoma or
invasion by extra-vesical neoplasms.
Benign strictures – congenital or post-inflammatory.
Mechanical – calculus or foreign body; cystocoele in females.
Neurogenic, e.g. in spinal cord injury.
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Answer 5
Renal calculi, acute pyelonephritis (which may be complicated by papillary necrosis),
septicaemia, renal failure.
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Answer 6
This is a latent carcinoma discovered incidentally in a TURP specimen for BPH. Followup only is required and therapy is not instituted. About 30% will progress after 10 years,
but there are no tests to identify this cohort.
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Answer 7
a)
These sections through a prostate removed via radical prostatectomy reveal
irregular yellowish nodules, mostly in the posterior portion (seen here
superiorly). This proved to be prostatic adenocarcinoma. Prostate glands
containing adenocarcinoma are not necessarily enlarged. Adenocarcinoma
may also coexist with hyperplasia. However, prostatic hyperplasia is not a
premalignant lesion. Staging of prostatic adenocarcinoma is based upon
how extensive the tumor is.
At the right are normal prostatic glands containing scattered corpora
amylacea. At the left is prostatic adenocarcinoma. Note how the glands of
the carcinoma are small and crowded. Prostatic adenocarcinomas are given
a histologic grade (Gleason's grading system is used most often, and
includes a score of 1 to 5 for the most prominent component added to a
score of 1 to 5 for the next most common pattern). For example, this
adenocarcinoma could be given a Gleason grade of 3/3.
At high magnification, the neoplastic glands of prostatic adenocarcinoma are
still recognizable as glands, but there is no intervening stroma and the
nuclei are hyperchromatic.
Prominent nucleoli are seen in the nuclei of this prostatic adenocarcinoma,
which is a characteristic feature.
By immunoperoxidase staining with antibody to prostate specific antigen
(PSA), this adenocarcinoma of prostate shows positivity. PSA is better
known as a serum test to detect males that may have prostate cancer.
b)
Histological Gleason grade and anatomical stage.
The tumour is graded from 1 (well-differentiated) to 5 (poorly differentiated).
Two grades are combined to give a Gleason score, e.g. grade 3+4=7. Scores
of 5 to 7 are commonly reported in needle biopsies of the prostate. Scores of
8 to 10 indicate advanced carcinoma, probably inoperable.
Staging indicates the extent of spread of the tumour.
c)
Diagnostic imaging is used to detect the spread and therefore stage of the
tumour.
Direct spread – extracapsular to surrounding tissues, especially seminal
vesicles.
Lymphatic spread – to sacral, iliac and para-aortic lymph nodes.
Blood spread – to bone (the vertebrae via the Batson system of veins, the
pelvis and femur), lung and liver.
Bony metastases in prostatic carcinoma are more likely to be osteosclerotic
than osteolytic. Bone alkaline phosphatase is often raised in the peripheral
blood indicating increased bone formation. With widespread involvement of
bone, a leukoerythroblastic anaemia may develop.
Prostate – specific antigen is usually markedly raised in patients with prostatic
carcinoma but levels may be low (or rarely normal) and overlap with levels
seen in benign conditions. Its greatest use is in detecting recurrence of tumour
following treatment.
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