Diagnostic ultrasound ( PDFDrive )

392 PART II Abdominal and Pelvic Sonography
Congenital cysts of the prostate occur in or close to the midline
and are related to the wolian (mesonephric or pronephric
[archinephric]) ducts or müllerian (paramesonephric) ducts 44
(Fig. 10.9B–C). Most men with congenital cystic lesions in the
prostate and SV are asymptomatic, but occasional symptoms
arise if the cysts become large or infected.
Congenital abnormalities are common in and around the
prostate and SVs. 42 he müllerian tubercle gives rise to the
prostatic utricle, a small, midline blind pouch situated near
the summit of the verumontanum. Prostatic utricle cysts are
caused by dilation of the prostatic utricle. Utricle cysts rarely
contain spermatozoa but can be associated with genitourinary
anomalies including unilateral renal agenesis, hypospadias, and
undescended testis. Utricle cysts are always in the midline and
are usually small but occasionally can enlarge to several centimeters
in diameter (see Fig. 10.9B–C). Müllerian duct cysts
may arise from remnants of the paramesonephric duct. Müllerian
duct cysts are usually small and usually midline but may extend
lateral to the midline and enlarge to extend above the prostate.
hey have no other associations and never contain spermatozoa.
As with utricle cysts, they have a teardrop shape pointing toward
the verumontanum, a thick visible wall, and occasional mural
or contained calciications. In practice, utricle and müllerian
cysts appear similar and their diferentiation is not important.
When large, both may obstruct ejaculatory ducts or develop
calciications (see Fig. 10.9E) and become painful or infected
and rarely may develop tumors. 43,44
Ejaculatory duct cysts are usually small and probably represent
cystic dilation of the ejaculatory duct, possibly as a result of
obstruction. Alternatively, they may be diverticula of the duct.
hey tend to be fusiform in shape and are typically pointed
at both ends. Ejaculatory duct cysts contain spermatozoa
when aspirated. hey can be associated with infertility and
may be seen in patients with a low sperm count. Some may
cause perineal pain. 43,44
Other disorders that mimic prostate cysts include SV cysts,
ectopic ureterocele, Cowper duct cysts (in urogenital diaphragm
below apex of prostate), and bladder diverticula.
Prostate abscesses are cystlike cavities with thick, irregular
walls and debris containing luid and resemble abscesses seen
elsewhere (see Fig. 10.8E). Coliform organisms such as E. coli
are the most common cause. Predisposing conditions include
diabetes, instrumentation, and immunodeiciency. Transrectal
aspiration or TURP drainage can be an efective treatment in
addition to antimicrobial therapy. 42-44 Cysts caused by parasites
are rare in Western countries and can result from schistosomiasis
(bilharziasis) or hydatid (echinococcal) disease. 42,43
Cystic neoplasms are rare, but cystadenoma and cystadenocarcinoma
have been described. 42,43
Seminal Vesicles and Vas Deferens
he seminal vesicles and vas deferens develop from the
mesonephric duct and are associated with renal and ureteric
development. Developmental anomalies of the SV/VD are oten
associated with renal and ureteric abnormalities. Normal SVs
measure about 1 × 5 cm, and VD, about 6 mm. he SVs function
to produce and secrete seminal luid and not to store sperm.
he vasa deferentia drain via the ejaculatory ducts through the
prostate into the verumontanum. Primary pathology of the
SV and VD is being increasingly detected with use of TRUS
and MRI. 45,46
Hypoplasia or agenesis of the SV occurs surprisingly commonly.
It may be unilateral or bilateral and can be associated
with agenesis or ectopia of the VD and ipsilateral kidney. Patients
with cystic ibrosis commonly have bilateral agenesis of the SV
and VD but normal kidneys. 45,46
Seminal vesicle cysts are rare and usually solitary (Fig. 10.10C).
Most are asymptomatic. he cysts can enlarge and become
symptomatic and can be aspirated with TRUS guidance. hey
may be associated with ipsilateral renal anomalies, including
renal agenesis, because the SVs are derivatives of the wolian
(mesonephric) ducts, which also give rise to the ureter and VD.
Congenital SV cyst and absence of the ipsilateral kidney is known
as Zinner syndrome. Other associations include adult polycystic
disease, hemivertebra, and ipsilateral absence of testis. he SV
is a common site of ectopic insertion of the ureter. 44,46,47
Calciication of the SV and VD can occur with diabetes or
infection. Diabetic calciication tends to involve the walls and
resembles “tram tracks” on x-ray ilms, whereas infectious or
inlammatory calciication is luminal and segmental and may
be associated with SV calciications. In endemic areas, tuberculosis
and schistosomiasis should be considered. 45,46
On occasion, a 1-cm-diameter eggshell calciication is seen
in the SV. hese calciications are asymptomatic and likely related
to inlammation.
Malignancy in the SV is most commonly secondary to carcinoma
of the prostate, bladder, or rectum and appears as a mass
involving the SV. If SV involvement is suspected at time of prostate
TRUS biopsy, then additional cores can be taken from the SV
and may alter treatment plans. Primary neoplasms of the SV are
very rare and include benign cystadenomas, leiomyoma, ibromas,
and others and malignant lesions such as adenocarcinoma. Tumor
mimics such as amyloid deposits are increasingly becoming
recognized. 45,47
INFERTILITY AND TRANSRECTAL
ULTRASOUND
Infertility is deined as failure to achieve pregnancy ater 1 year
of regular unprotected intercourse and afects about 15% of
couples. Male factors are solely responsible in about 20% of
couples and contributory in another 30% to 40%. When present,
male infertility is usually but not always detected by abnormal
semen analysis. he AUA and the European Association of
Urology have deined “best practice” policies for investigating
male infertility, and both partners should be evaluated simultaneously.
48,49 he goals of male evaluation include the following:
1. Identiication of potentially correctable conditions
2. Identiication of irreversible conditions for which alternative
treatments (e.g., donor insemination) or adoption may be
used, preventing inefective therapies
3. Detection of health-threatening conditions underlying
infertility