Diagnostic ultrasound ( PDFDrive )

1904 PART V Pediatric Sonography
hyperechoic, or heterogeneous. Ultrasound cannot clearly distinguish
benign from malignant lesions. 189 Increased vascularity
on Doppler imaging in a paratesticular rhabdomyosarcoma may
mimic that seen with epididymitis. 186 hus follow-up should be
performed in cases of suspected epididymitis to ensure resolution
of any mass because rhabdomyosarcoma can manifest this way. 189
he most common benign paratesticular masses include
adenomatoid tumors as well as luid-illed masses, such as
spermatoceles and cysts of the epididymis or tunica albuginea.
Adenomatoid tumors are usually seen in the body of the epididymis
and less oten in the spermatic cord or testicular tunics.
hey are solid, well-circumscribed, with variable echogenicity.
Epididymal cystadenomas (associated with von Hippel–Lindau
disease) 190 and lymphangiomas are septated cystic masses. 182,191
With splenogonadal fusion, a rare congenital anomaly, a mass
of ectopic splenic tissue may be noted adjacent to the let testis. 192
Focal calciications from meconium periorchitis may appear
as palpable scrotal masses (Fig. 54.53). hese dystrophic calciications
result from in utero bowel perforation during the second
or third trimester of gestation. Sterile intestinal contents (meconium)
leak into the peritoneal cavity and enter the scrotum
through a patent processus vaginalis and elicit a foreign body
T
inlammatory response that results in focal calciications. As
with calciication elsewhere, these areas are echogenic with strong
posterior shadows and may mimic a solid neoplasm, particularly
a teratoma. Diferentiation is based on the inding of additional
intraperitoneal calciications on sonography or plain ilm radiography
of the abdomen. 189 Eventually, spontaneous regression
of these calciications occurs, and thus conservative management
is recommended. 193 Diferential diagnosis of scrotal or testicular
calciications in the pediatric patient includes teratoma, gonadoblastoma,
Leydig cell tumor, testicular microlithiasis, calciied
loose bodies, phleboliths, meconium peritonitis, calciied hematomas,
and postinlammatory or infectious scrotal calculi.
Testicular microlithiasis is an asymptomatic condition that
has a characteristic sonographic appearance and usually is
discovered incidentally. It has been reported in normal patients
and those with Down syndrome, cryptorchidism, and Klinefelter
syndrome. Testicular microlithiasis represents calciied debris
within the seminiferous tubules. he cellular debris has a calciic
core and surrounding lamellated collagen, resulting from a failure
of Sertoli cell phagocytosis. On ultrasound there are tiny (1-3 mm),
hyperechoic, most oten nonshadowing foci 189 (Fig. 54.54, Video
54.5). he number of echogenic foci within the testis can range
from a few to many, but at least ive microliths on a single image
should be visualized to meet ultrasonographic criteria. 194 he
association between testicular microlithiasis and malignancy
remains unclear. Ultrasound follow-up should be considered in
symptomatic patients, in patients with a history of malignancy,
or on patient request. Self-examinations can be used to follow
asymptomatic patients. 195
FIG. 54.53 Meconium Periorchitis in 5-Year-Old Boy With Painless
Scrotal Masses. Sagittal view of the left hemiscrotum using a stepoff
pad shows two well-deined, oval, brightly echogenic masses with
hypoechoic halos and acoustic shadows, which lie inferior to the normal
left testis (T). (With permission from Mene M, Rosenberg HK, Ginsberg
PC. Meconium periorchitis presenting as scrotal nodules in a ive year
old boy. J Ultrasound Med. 1994;13[6]:491-494. 193 )
LOWER URINARY TRACT
Congenital Anomalies
Duplication anomalies of the collecting systems and ureters are
the most common congenital anomalies of the urinary tract. In
complete ureteral duplication the lower ureter inserts orthotopically
into the trigone, oten resulting in vesicoureteral relux.
he upper-pole ureter usually inserts ectopically in the bladder
(at the bladder neck) or in the trigone (inferomedial to the normal
location). It can also insert into the urethra, vagina, or uterus
A
B
FIG. 54.54 Testicular Microlithiasis. Transverse image of both testicles (A) and sagittal image of the right testicle (B) in an 18-year-old male
with testicular pain reveal multiple punctate echogenic foci without acoustic shadowing. See also Video 54.5.