Diagnostic ultrasound ( PDFDrive )

CHAPTER 48 The Pediatric Head and Neck 1657
prenatally, with 90% presenting by age 2 years. Clinically, the
skin is usually normal but may have a bluish hue, puckering, or
tiny vesicles. 163 hese lesions can be difuse or focal, tend to
invade multiple anatomic facial planes, and will rapidly enlarge
if complicated by hemorrhage or infection. Hypertrophy and
intraosseous invasion of adjacent bone, usually the mandible,
can occur.
About 75% of lymphatic lesions occur in the neck, and most
originate within the posterior triangle or oral cavity, with lesions
occurring on the let side twice as oten as on the right side. 43,48,82
Of infants with lymphatic malformations, 3% to 10% have airway
compromise from respiratory obstruction or mediastinal extension.
47,157 Although most children with lymphatic malformation
have a normal karyotype, several syndromes are associated, such
as Turner, Down, Noonan, Roberts, and trisomy 13 and 18. 144
On ultrasound, most lymphatic malformations are multiloculated
cystic masses with septa of variable thickness and solid
components 47 (Fig. 48.49, Video 48.4). Fluid-luid levels or
echogenic debris can result from superimposed hemorrhage or
infection. MRI provides optimum tissue characterization
and lesion delineation before surgical intervention. 168 Surgical
resection is the treatment of choice but can be diicult if the
lesion invades neural, vascular, and muscular structures; therefore
sclerotherapy, radiofrequency ablation, and laser therapy are
other options. 48,168 Other malformations involving the lymphatic
system include generalized lymphatic anomaly, Gorham-Stout
disease, channel-type lymphatic malformation, primary lymphedema,
and others. 162
Venous malformations are sot, compressible lesions that
may distend with increased venous pressure (Valsalva maneuver).
About 40% of these lesions occur in the head and neck, and
many invade multiple fascial planes and involve osseous structures.
163 hese lesions, appearing clinically as sot, bluish,
compressible masses, consist of thin-walled, dilated, dysplastic,
small and large venous channels deicient in smooth muscle. 43
Rapid enlargement may occur secondary to phlebothrombosis.
Multiple venous malformations are seen in Mafucci syndrome
and blue rubber bleb nevus syndrome, cerebral cavernous
malformation, and glomuvenous malformation. 162,169 Phleboliths
are present in 16% of cases and can help conirm the
diagnosis. Ultrasound demonstrates hypoechoic lesions with
heterogeneous architecture. Acoustic shadowing secondary to
phleboliths and luid-luid levels may be identiied 48 (Fig. 48.50).
On Doppler sonography, venous low-velocity low is identiied.
Treatment includes elastic compression, sclerotherapy, and surgical
excision.
Arteriovenous malformations (AVMs) represent collections
of a nidus of tortuous abnormal, thin-walled vessels connecting
dilated feeding arteries to draining veins. hese lesions may be
centered in cutaneous, muscular, or intraosseous structures.
FIG. 48.49 Lymphatic Malformation. Lymphatic malformation in
a 5-year-old child with long-standing left neck mass. Ultrasound shows
a multilocular cystic lesion with a luid-luid level in one of the locules,
indicating internal hemorrhage. See also Video 48.4.
A
B
FIG. 48.50 Venous Malformation. (A) Side-by-side gray-scale and color Doppler. Masseter muscle is enlarged and heterogeneous with
hypoechoic areas and a hyperechoic focus that shadows (arrowhead), consistent with phlebolith. Color Doppler demonstrates mild increase in
vascularity. (B) Axial T2-weighted fat-saturated magnetic resonance image demonstrates high-signal lesion iniltrating the masseter muscle and
parapharyngeal space. Dark foci are consistent with phleboliths (arrows).