Diagnostic ultrasound ( PDFDrive )

CHAPTER 48 The Pediatric Head and Neck 1645
A
B
FIG. 48.28 Complex Thyroglossal Duct Cyst. (A) Sagittal color Doppler image of a complex cystic avascular lesion anterior to the trachea
and superior to the isthmus of the thyroid. The lesion is hypoechoic with debris inferiorly. (B) Gray-scale axial ultrasound demonstrates heterogeneous
mass with both hypoechoic and isoechoic components.
A
B
FIG. 48.29 Type IV Branchial Sinus Abscess. (A) Hypoechoic, poorly deined collection in left anterior neck distorting muscle and soft tissue
planes, compressing the left thyroid gland. (B) Axial computed tomography scan at same level demonstrates inhomogeneously enhancing phlegmon
adjacent to left lobe of the thyroid.
considered 101,102 (Fig. 48.29). hese patients usually are presented
at age 2 to 12 years with fever, sore throat, and swelling in the
lower neck. On ultrasound, the let lobe of the thyroid gland
may be heterogeneous. If an abscess has developed, typically a
focal hypoechoic lesion is surrounded by hyperemia in the let
perithyroid area. 87,90,101,102
de Quervain thyroiditis, also known as focal thyroiditis,
is an uncommon form of subacute thyroiditis likely
caused by a viral infection. 83 Granulomatous inlammation
of the gland can result in thyromegaly and heterogeneous
echogenicity.
Hashimoto thyroiditis is the most common cause of thyroid
disease in children and adolescents. 74 It is an autoimmune disorder
caused by circulating antibodies. Injury to the gland results in
a difuse lymphocytic and plasma cell iniltration. he process
is more common in girls than in boys, with a family history of
thyroid disease in one-fourth of cases. 88,103 Clinically, the patient
has painless enlargement of the thyroid. Although in the acute
phase the patient may be hyperthyroid, most patients are hypothyroid
at presentation. Hashimoto thyroiditis may be associated
with several syndromes (e.g., Turner, Noonan, Down) and has
been described in patients with juvenile diabetes, those receiving
phenytoin therapy, and those with Hodgkin disease. 87 On
ultrasound, the gland is enlarged with lobular margins and
contains coarse septations and multiple hypoechoic micronodules
measuring 1 to 6 mm in diameter 90 (Fig. 48.30). Normal, increased,
or deceased color Doppler waveforms may be present. Adjacent
cervical adenopathy is oten noted. he majority of these patients
have spontaneous resolution of symptoms. Suspicious nodules
identiied on thyroid ultrasound in the setting of Hashimoto
thyroiditis are generally followed owing to increased risk of
malignancy. 104,105