Diagnostic ultrasound ( PDFDrive )

1826 PART V Pediatric Sonography
A
B
C
D
FIG. 52.74 Neuroblastoma in 4-Month-Old Boy With Stage IV Disease. (A) Longitudinal gray-scale image demonstrates a heterogeneous,
lobulated mass arising from the left adrenal gland (M) and compressing the upper pole of the left kidney (LK). (B) Transverse gray-scale image
depicts the mass crossing the midline and encasing the aorta (A). The mass contains calciications with associated distal shadowing (arrows). (C)
Longitudinal color Doppler image shows hypovascularity of the mass (M) compared with the underlying left kidney (LK). (D) Longitudinal gray-scale
image of the liver (L) depicts three hyperechoic metastatic deposits (arrows). RK, Right kidney. See also Video 52.9.
develop neurologic symptoms postoperatively, including paralysis,
if the tumor is not carefully resected.
Pheochromocytoma
According to the World Health Organization classiication of
endocrine tumors, a pheochromocytoma is an intraadrenal
paraganglioma arising from catecholamine-producing chromain
cells in the adrenal medulla. 231,232 hese tumors may occur sporadically,
or as a component of a hereditary tumor syndrome,
including von Hippel–Lindau disease, multiple endocrine
neoplasia (MEN) types IIA and IIB, and the familial paraganglioma
syndromes. Rarer associations include neuroibromatosis
type 1, MEN type I, tuberous sclerosis complex, and Carney
triad. 231,233
About 56% of apparently sporadic pheochromocytomas in
children 18 years of age or younger are caused by a mutation in
the germline DNA, and the percentage of children younger than
10 years of age with hereditary disease is as high as 70%. 234
Hereditary pheochromocytoma is oten bilateral and is more
common in children than adults. 235,236
Pheochromocytoma in children usually is discovered as
a result of catecholamine hypersecretion, because of tumor
mass efect, as an incidental inding at imaging, or ater family
screening for one of the hereditary syndromes. Signs and
symptoms suggestive of pheochromocytoma include sustained
hypertension, paroxysmal episodes of headache, palpitations and
diaphoresis, pallor, orthostatic hypotension and syncope, tremor,
and anxiety. 231 Quantiication of plasma free metanephrine and
normetanephrine, or measurement of 24-hour urinary fractionated
metanephrines are the most accurate biochemical tests used
for diagnosis of pheochromocytoma in adults. Although fewer
studies have been performed in children, metanephrine quantiication
is thought to be a superior method in this population
as well. 237
At sonography, a pheochromocytoma will appear as a solid,
highly vascular, round or oval mass of variable echogenicity. 225