Diagnostic ultrasound ( PDFDrive )

CHAPTER 54 Pediatric Pelvic Sonography 1897
Appendix
epididymis
Appendix
testis
Appendix
vas
A
FIG. 54.41 Torsion of Appendix Epididymis in 12-Year-Old Boy
With 10 Hours of Scrotal Pain. Transverse power Doppler image
through the superior scrotum reveals an enlarged paratesticular mass
with no vascularity consistent with a torsed epididymal appendix. Flow
is detected in the adjacent testicle, excluding testicular torsion.
B
FIG. 54.40 Testicular Appendages. (A) Appendix testis, appendix
epididymis, and appendix vas (vas aberrans of Haller). (B) Transverse
image in a normal male through the epididymal head shows the epididymal
appendage to be an isoechoic nodule adjacent to but separate from the
head. (A with permission from Leape LL. Torsion of the testis. In: Welch
KJ, Randolph JG, Ravitch MM, editors. Pediatric surgery. St. Louis,
1986, Mosby. 123 )
In younger boys, epididymitis is more oten secondary to
genitourinary abnormalities, such as ectopic ureter draining into
the vas deferens or seminal vesicles. 137 Bladder outlet obstruction
(e.g., posterior urethral valve and dysfunctional voiding) can
cause relux of urine into the ejaculatory ducts and lead to
epididymitis even if the urine is sterile. 128,138 Epididymitis may
also follow trauma. With epididymitis, patients typically have
a more gradual onset of symptoms and fewer constitutional
symptoms than with torsion. here may be mild scrotal tenderness
to severe scrotal pain and tenderness with fever and pyuria. In
adolescent boys, most cases are secondary to sexually transmitted
organisms (e.g., C. trachomatis, N. gonorrhoeae). In young boys,
Escherichia coli is found in 10% to 25% of patients. 114,136
Torsion of a testicular appendage, or appendix epididymis,
is the most common cause of acute scrotal pain in prepubertal
boys, with an incidence of 26% to 67% peaking between 6
and 12 years of age 88,138,139 (Fig. 54.40). Torsion of a testicular
appendage may produce the same clinical signs and symptoms
of testicular torsion or epididymitis, but there is generally no
nausea and vomiting. If the classic clinical inding of a small,
irm, round, mobile, tender paratesticular mass, which oten
exhibits bluish discoloration visible through the skin (blue-dot
sign), in the superior aspect of the scrotum is not found, then
ultrasound is recommended to avoid unnecessary surgery. 97,140,141
he diagnostic sonographic appearance of a torsed appendage
is that of a solid, ovoid mass with a variably sized hypoechoic
center and hyperechoic rim adjacent to the superior aspects of
a testis or epididymis that is avascular 138,142 (Fig. 54.41). Reactive
hydroceles, scrotal skin thickening, testicular and epididymal
enlargement, and hypoechogenicity may be seen, as well. 142,143
In acute torsion of an appendix, the torsed appendix appears
avascular and the epididymis hyperemic. In late torsion (>1
day), a zone of reactive hyperemia may surround the torsed
appendage. 140,141 Depending on the extent of the associated
inlammatory process, the testis may have normal or increased
vascularity. 90,142-145 he testicular appendages are embryologic
remnants of blind-ending mesonephric tubules. 138 he appendix
testis is attached to the tunica albuginea on the superior pole
of the testis, and the appendix epididymis is located on the
epididymal head. Both appendages are pedunculated and thus
predisposed to torsion; 92% of males have an appendix testis,
and 25% have an appendix epididymis. 97 Most torsed appendices
atrophy, with resolution of symptoms with supportive care. Surgery
is reserved for persistently symptomatic appendages. Eventually,
infarcted appendages shrink in size, may calcify, and may break
free to become scrotoliths. 90,139
Trauma to the scrotum most oten results from sporting
injuries but may be seen in straddle or handlebar injuries, motor
vehicle crashes, child abuse, or birth trauma. Trauma can cause
a testicular hematoma, fracture, or rupture. 146,147 Testicular rupture
is a surgical emergency. Improved salvage rates have been shown
if surgery to repair a ruptured testis is performed within 72
hours of the traumatic event. 138 Sonographic indings of rupture
(Fig. 54.42) include difuse parenchymal heterogeneity with loss
of a normal, smooth contour and disruption of the tunica