Diagnostic ultrasound ( PDFDrive )

CHAPTER 54 Pediatric Pelvic Sonography 1899
low to the scrotal wall with normal low to the testes and epididymides.
122,148-151 Acute scrotal edema resolves spontaneously
within several days without sequelae.
Scrotal or testicular involvement is estimated in 15% of patients
with Henoch-Schönlein purpura, a vasculitis involving small
vessels and afecting the skin, gastrointestinal tract, joints, and
kidneys. Sonographic indings include difuse swelling of the
scrotum and contents with intact testicular low, obviating the
need for surgery in this entity, which usually resolves spontaneously
and completely. 152 he echotexture of the testes is normal,
but there is generally bilateral epididymal enlargement with a
heterogeneous echo pattern, reactive hydrocele, and scrotal wall
thickening. 150,151 Color Doppler imaging reveals hypervascularity,
especially in the thickened scrotal wall and epididymis with
normal intratesticular low. 153 Careful examination for the classic
purpuric rash over the buttocks, lower extremities, and perineum
aids in diagnosis. 92
Scrotal swelling and pain may also be secondary to an
intraabdominal process, especially in neonates with a patent
processus vaginalis. Various luids, such as blood, chyle, pus,
dialysis luid, cerebrospinal luid from ventriculoperitoneal shunt,
or other intraperitoneal luids can drain into the scrotum. Blood
from the abdomen can enter the scrotum through extravasation
into the tissue planes or through a patent processus vaginalis
and can be the presenting sign in patients with adrenal hemorrhage,
109 hepatic laceration, or delayed splenic rupture in a battered
child. Scrotal swelling has been reported in association with
inlammatory or infectious conditions, such as acute appendicitis,
perforated appendicitis, 108 or Crohn disease. 111 Another unusual
cause for scrotal swelling is testicular vein thrombosis from a
femoral venous line during cardiac catheterization. In the neonate
with scrotal swelling and in older children with scrotal swelling
of uncertain cause, abdominal sonography may help diagnose
a primary abdominal event as the cause for secondary scrotal
pathology. 109
SCROTAL MASSES
Intratesticular Causes
Sonography plays an important role in the evaluation of scrotal
masses by conirming the presence of a lesion, determining its
site of origin, and characterizing its contents. Ultrasound has
almost 100% sensitivity in detecting testicular tumors. 154,155
Ultrasound is able to distinguish intratesticular from extratesticular
tumors in 90% to 100% of cases. 103 his distinction is
important because most intratesticular masses are malignant
and most extratesticular masses are benign. Benign and malignant
testicular tumors are the seventh most common neoplasm
in children. About 80% of testicular tumors are malignant. In
the pediatric age group, there are two peak incidences of testicular
neoplasms: in children younger than 2 1 2 years (60%) and
in late adolescence (40%). he incidence of malignancy in a
cryptorchid (abdominal) testis is increased by a factor of 30 to
50. Both seminomas (malignant) and gonadoblastomas (the
majority of which are benign) oten develop in dysplastic gonads
associated with undescended testes, testicular feminization
syndrome, male pseudohermaphroditism, and true
hermaphroditism. 151
Testicular tumors account for about 1% of all childhood
neoplasms and for 2% of solid malignant tumors in boys. 156,157
Primary testicular neoplasms are divided into those of germ
cell and non–germ cell origin. In prepubertal children, 70% to
90% of primary testicular neoplasms are of germ cell origin, and
most of these (66%-82%) are endodermal sinus tumors (yolk
sac carcinomas). Yolk sac tumor is localized to the scrotum at
presentation in most patients (≥80%). 156,157 he remaining 20%
of patients have lymphatic spread to regional and retroperitoneal
lymph nodes or hematogenous spread to distant sites. Survival
is 70% or greater with disease restricted to the testis. 156 Embryonal
cell carcinomas, teratocarcinomas, and choriocarcinomas are
more aggressive tumors and metastasize early through lymphatic
and hematogenous routes. Endodermal sinus tumors occur
primarily as a painless scrotal mass in infants 12 to 24 months
of age. here may be an associated ipsilateral hydrocele (25%)
or inguinal hernia (21%). he tumor may metastasize to the
lungs, especially in older children, but retroperitoneal lymph
node metastasis is rare. Embryonal carcinoma usually occurs
in adolescence or young adulthood. It is highly malignant and
usually spreads to retroperitoneal and mediastinal lymph nodes,
with hematogenous metastases to the lung, liver, and brain. 151
Elevated serum alpha-fetoprotein levels are common in yolk sac
and embryonal cell tumors, whereas elevated serum levels of
β-hCG are seen most oten with embryonal cell tumors and
teratocarcinomas. 156,157
he remaining germ cell tumors seen in adolescents and
adults are benign teratomas, teratocarcinomas, and choriocarcinomas.
156 Testicular teratoma is the most common benign
germ cell tumor of the testis in infants and young children.
Teratomas are most oten seen in children younger than 4 years.
Patients with testicular neoplasms usually have painless scrotal
or testicular enlargement. Pain secondary to torsion or hemorrhage
into the tumor is rare. 99 About 85% of benign teratomas
contain well-diferentiated elements from all three germ cell layers.
here are poorly diferentiated elements in approximately 15%
of these tumors, but even so, the tumor usually has a benign
course. 156 In pubertal patients, however, teratomas are oten
malignant and tend to behave more aggressively, necessitating
orchiectomy.
Seminoma, the most common testicular tumor in adults, is
rare in children, is most oten associated with cryptorchidism,
and when present, is usually in adolescents. In general, seminomas
are uniformly hypoechoic masses, rarely containing areas of
necrosis and hemorrhage 103,158 (Fig. 54.44). On the other hand,
teratomas and teratocarcinomas are complex masses with
hypoechoic areas from serous luid and hyperechoic areas representing
fat and calciications. 103,157-159 he remaining germ cell
tumors have nonspeciic, variable appearances. 158 When the tunica
is invaded by aggressive tumors, the testicular contour appears
irregular. Testicular tumors are accompanied by reactive hydroceles
in 20% to 25% of cases. 156,160 he scrotal skin is rarely
thickened in the presence of tumors, and when observed in the
presence of a mass, is usually indicative of an inlammatory
process.