The seminal vesicles are paired secretory glands just
posterior to the bladder. Normal seminal vesicle dimensions
are 3cm in length (±0.5cm), 1.5cm in width (±0.4cm). The
shape of the seminal vesicle is variable; they may be round,
tubular, or ovoid
4. The function of seminal vesicle is
important for fertility. Parameters as sperm motility, sperm
chromatin stability, and immuno-protection may be changed
in case of its hypofunction
5.
Anomalies of the seminal vesicles can be categorized in
to abnormalities of number (agenesis, fusion), canalization
(cysts) and maturation (hypoplasia)6. Seminal vesicle
lesions are uncommon, but it may be detected more
commonly with increased use of TRUS, CT or MRI, and it
should be considered when evaluating males with pelvic
masses. There are many causes of pelvic masses in males.
Small cysts may occur in the prostate, ejaculatory duct, or
cowper gland. Mullerian duct or utricle cysts are not
uncommon, but are midline. Tumors may arise in bladder,
prostate, urethra, or other pelvic structures including, rarely,
the seminal vesicle. Abscesses may occur in a variety of
locations4,7,8.
Early imaging of the seminal vesicles was accomplished
by seminal vesiculography. Although it is still regarded
as the gold standart for visualizing the male reproductive
tract, it is invasive and carries with a risk of damage to the
vas deferens. Therefore, seminal vesiculography is generally
used prior to definitive surgery for obstruction. Recently,
TRUS has replaced seminal vesiculography as diagnostic
technique of choice in the evaluation of male pelvic
reproductive anatomy. TRUS is indicated in infertile patients
with low volume azoospermia and low volume
oligoasthenospermia as well in men with painful ejaculation
or recurrent hematospermia. CT can very accurately show the
intennal pelvic organs; thus absence of seminal vesicles or
mass arising in them is easily detectable by CT4,7,8. MRI
has contributed to more precise imaging of the seminal
vesicles. In MRI imaging, normal seminal vesicle signal
intensity is similar to that of muscle or bladder on T1
weighted images. On T2 weighted MRI images, the seminal
vesicles display high signal intensity that is greater than that
of the surrounding fat. CT and MRI should be reserved for
more complex situations and pre-surgical intervention4,8.
The application of TRUS has assumed a significant role in
the imaging of seminal vesicles. TRUS is more readily
available and economical according to CT and MRI4,9. In
the present case, TRUS was performed to the patient for
initial evaluation, and it showed absence of left seminal
vesicle and hypoplastic right seminal vesicle with ovoid
cystic shape. CT and MRI were also demonstrated no left
seminal vesicle and hypoplastic right seminal vesicle.
Similarly the other reports, T1 weighted image of MRI
showed the hypoplastic right seminal vesicle the same signal
intensity as muscle or bladder.
Agenesis of seminal vesicle is unreconstractable and
reguires no surgical or medical treatment. Microsurgical
epididymal aspiration or testicular sperm extraction
combined ICSI have provided a viable treatment strategy for
the management of such cases10. Similarly, Microsurgical
epididymal aspiration or testicular sperm extraction
combined ICSI was recommended to the patient.
In conclusion, absence of unilateral seminal vesicle
associated with contralateral hypoplasia of seminal vesicle is
a rare situation. The diagnostic work-up consists of TRUS,
CT and MRI. TRUS may be good method for initial
evaluation of these such anomalies. However, CT and MRI
should be reserved for selected patients when the result of
TRUS is not conclusive. In such cases, assisted reproductive
techniques should be recommended to the patient for children.