Diagnostic ultrasound ( PDFDrive )

CHAPTER 54 Pediatric Pelvic Sonography 1887
however, this pattern may also be seen in other cystic lesions. 21,72
In extensive cases of PID the pelvis is difusely illed with a
heterogeneous echo pattern containing cystic and solid components
that obscure tissue planes and uterine margins.
A complication of PID is gonococcal or chlamydial perihepatitis
(Fitz-Hugh–Curtis syndrome). he patient has right
upper quadrant pain caused by localized peritonitis of the anterior
liver surface and parietal peritoneum of the anterior abdominal
wall. Sonographic indings include the presence of ascitic luid
and thickening of the right anterior extrarenal tissue between
the liver and right kidney. 74,75
Foreign Bodies
A vaginal discharge may be a sign of vaginal infection or trauma.
Foreign bodies in the vagina are a cause of 4% of cases of vaginitis.
A wad of toilet paper is the most common foreign body in the
vagina in the pediatric population. Vaginal foreign bodies are
seen in 18% of children with vaginal bleeding and discharge and
in 50% of children with vaginal bleeding and no discharge.
Sonography, either transabdominal or transperineal, with or
without water vaginography, can identify both radiopaque and
nonradiopaque foreign bodies within the vagina as echogenic
material with distal acoustic shadowing. A retained vaginal foreign
body can be demonstrated on sonography as a slight indentation
on the posterior bladder wall. Acoustic shadowing is characteristic
but may not be present. 76,77
ENDOCRINE ABNORMALITIES
Ultrasound is integral to the evaluation of children with endocrine
abnormalities. In the newborn with ambiguous genitalia, pelvic
sonography can quickly determine the presence or absence of
the uterus and vagina. Identiication of the ovaries or testes is
more diicult because normal neonatal ovaries are diicult to
visualize with ultrasound. Using a high-resolution (12-17 MHz)
linear transducer, the gonads may be found in the inguinal canal
or in the ambiguous labioscrotal folds. Diferentiation of the
gonads between ovaries and testes may be possible because ovaries
oten have small, hypoechoic follicles and testes have a solid,
homogeneous echotexture. 78
Causes of Primary Amenorrhea
Sonographic assessment of the uterine size, shape, and maturity
and ovarian development can provide a clue to the many causes
of primary amenorrhea. A small or absent uterus may be an
indication of gonadal dysgenesis, chromosomal abnormalities,
decreased hormonal states, testicular feminization, or isolated
uterine hypoplasia or agenesis. In Turner syndrome (45,XO
karyotype), the most common form of gonadal dysgenesis, there
is delayed or absent puberty associated with short stature, webbed
neck, renal anomalies, and coarctation of the aorta. Turner
syndrome is almost always mosaic (45,XO/46,XX). he ovaries
vary from nonvisualized streak ovaries to normal-appearing
ovaries. he uterine coniguration also varies from prepubertal
to an intermediate length that is less than that of the normal
adult female. Cleeman and colleagues 79 demonstrated in a group
of 41 patients with Turner syndrome that one or both ovaries
were detected in 37% by ultrasound. he mean ovarian volume
was lower in those with Turner syndrome than in the controls
(p = .001) (1.1 mL vs. 11.52 mL). he mean uterine volume was
not signiicantly diferent from that in the normal controls.
Other forms of gonadal dysgenesis are also associated with
nonvisualization of the ovaries as a result of absent or streak
gonads. In pure gonadal dysgenesis (Swyer syndrome), the
patients have 46,XX or 46,XY karyotypes and normal height.
Mixed gonadal dysgenesis is a genetic mosaic of karyotypes
45,XO/46,XY with a streak ovary and a contralateral intraabdominal
testicle. Both these forms of gonadal dysgenesis have
an increased risk of gonadal tumors as a result of the presence
of the Y chromosome. Noonan syndrome (pseudo–Turner
syndrome) is characterized by phenotypic changes of Turner
syndrome, normal ovarian function, and normal ovaries on
ultrasound.
Testicular feminization is another cause of primary amenorrhea.
It is a sex-linked recessive abnormality, resulting in endorgan
insensitivity to androgens. hese patients are phenotypic
females with a 46,XY karyotype. he uterus and ovaries are absent,
the vagina ends blindly, and the testes are ectopic (usually pelvic
or within inguinal canals or in labia majora).
Precocious Puberty
Precocious puberty is the development of secondary sexual
characteristics, gonadal enlargement, and ovulation before age
8 years. In true precocious puberty, the endocrine proile is similar
to that of normal puberty, with elevated levels of estrogen and
gonadotropins. he uterus has an enlarged, postpubertal coniguration
(fundus-to-cervix ratio of 2 : 1 to 3 : 1) with a more
prominent echogenic endometrial canal than seen in prepubertal
females. he ovarian volume is greater than 1 mL, and functional
cysts are oten present. Precocious puberty is classiied into two
types: central and peripheral. Central precocious puberty (true
precocious puberty) is gonadotropin dependent. 80,81 More than
80% of these cases are idiopathic. Intracranial tumors, usually
a hypothalamic glioma or hamartoma, account for 5% to 10%
of cases. here are occasional cases that follow development of
increased intracranial pressure, such as postmeningitis hydrocephalus.
he augmented uterine and ovarian volumes shown
on ultrasound occur before the typical changes in secretion
patterns of luteinizing hormone (LH) and follicle-stimulating
hormone (FSH) revealed with the luteinizing hormone–releasing
hormone (LHRH) test. Pelvic sonography during treatment with
long-acting gonadotropin-releasing hormone analogues will show
decreased uterine and ovarian volume compared with pretreatment
values, and the hormonal status will become appropriate
for age. 82,83
In pseudoprecocious puberty, the peripheral type, the
endocrine proile is variable because this type is gonadotropin
independent. Usually, the estrogen levels are elevated and the
gonadotropin levels are low. he cause is outside the hypothalamicpituitary
axis—usually an ovarian tumor. Granulosa tumor is
the most common lesion. Other, less frequent causes are functioning
ovarian cysts, dysgerminoma, teratoma, and choriocarcinoma.
Ultrasound will identify the ovarian mass and a mature
uterus.