Diagnostic ultrasound ( PDFDrive )

CHAPTER 52 The Pediatric Urinary Tract and Adrenal Glands 1825
on color Doppler imaging. Over several weeks, the hemorrhage
becomes anechoic, relecting blood clot lysis and liquefaction
(Fig. 52.73). he hemorrhage gradually decreases in size and
may result in adrenal calciication. Diferentiation from a neonatal
neuroblastoma is important. 226 Follow-up demonstrating a
progressive decrease in size and eventual resolution conirms
the diagnosis of an adrenal hemorrhage.
Neuroblastoma
Neuroblastoma is the most common extracranial solid tumor
of childhood. It arises from neural crest tissue and represents
the malignant end of a spectrum of related tumors that includes
the benign ganglioneuroma and ganglioneuroblastoma, an
intermediate-grade neoplasm with mixed histology. Neuroblastoma
may demonstrate spontaneous regression from
an undiferentiated state to a totally benign appearance. It is
classiied into three risk categories: low, intermediate, and high
risk. Low-risk disease is common in infants and good outcomes
frequently occur with observation or surgery. High-risk
disease is very diicult to treat successfully, even with intensive,
multimodal therapy. 227 Neuroblastoma is associated with the
Beckwith-Wiedemann syndrome, Hirschsprung disease,
neuroibromatosis type 1, DiGeorge syndrome, and central
hypoventilation syndrome. 228
Two-thirds of the time, neuroblastoma develops in the
abdomen, with approximately two-thirds of the tumors arising
from the adrenal gland. he remainder may develop anywhere
along the sympathetic nerve chain. 229 In the majority of children
with neuroblastoma the disease is found between 1 and 5 years
of age, with the most common age at presentation being 18
months. Boys and girls are equally afected. 230
At sonography, adrenal neuroblastoma is heterogeneous in
echotexture, with irregular, hyperechoic areas caused by calciication.
Its margins tend to be poorly deined. Extension of tumor
around the aorta and celiac and superior mesenteric arteries
helps to distinguish neuroblastoma from Wilms tumor, which
is usually well deined and relatively homogeneous in echotexture
(Fig. 52.74, Video 52.9). Sonography needs to be followed by
CT or MRI for disease staging. MRI is particularly useful because
the tumor can extend into the spinal canal and cause neurologic
symptoms. It is critical to know if this extension has occurred
before the tumor is surgically removed because the child may
A
B
C
D
FIG. 52.73 Neonatal Adrenal Hemorrhage. (A) and (B) Longitudinal gray-scale images of the right lank demonstrate a suprarenal hypoechoic
“mass.” The overall shape of the adrenal gland is preserved and there is peripheral calciication (arrows). A, Adrenal; K, kidney; L, liver. (C) Longitudinal
color Doppler image demonstrates the avascular nature of the adrenal lesion. (D) Longitudinal gray-scale image 18 months later reveals complete
involution of the “mass” and replacement by dense calciication with distal shadowing (arrows), typical of a resolved hemorrhage.