Diagnostic ultrasound ( PDFDrive )

CHAPTER 48 The Pediatric Head and Neck 1635
A
B
C
FIG. 48.14 Chronic Parotid Sialadenitis Secondary to Sialolithiasis. (A) Parotid contains round areas of decreased echogenicity typical of
dilated ducts and small areas of increased echogenicity consistent with mucus and small calculi (arrowheads). (B) Computed tomography scan
shows multiple calculi in the right and left parotid (arrowheads) and inhomogeneous density of the right parotid. (C) Sialogram excludes stone
obstructing Stensen duct but shows pooling in peripheral dilated ducts, sialectasis (arrow).
uveitis, and facial paralysis. 20 Calciied hypoechoic lesions may
be present. Treatment is primarily with steroids.
Salivary glands can also be involved in the spectrum of
immunoglobulin G4 (IgG4)–associated disease (IgG4-associated
disease), a systemic disease characterized by abundant iniltration
of IgG4-positive plasma cells and lymphocytes with associated
ibrosis resulting in multiorgan dysfunction. 31 here can be
multiple sites of involvement in the head and neck. Mikulicz
disease and chronic sclerosing sialadenitis (Küttner tumor) are
the two manifestations of IgG4-associated disease in the salivary
glands. 31 Both these conditions are more common in elderly
men, but pediatric cases of Küttner tumor have been reported. 32-34
Mikulicz disease is characterized by painless swelling of the
parotid, submandibular, and sublingual salivary glands, as well
as the lacrimal glands. Küttner tumor is a hard masslike enlargement
frequently involving the submandibular glands, either
unilateral or bilateral. 31 In Mikulicz disease, sonography reveals
multiple hypoechoic areas in enlarged salivary glands. 35 On
sonography Küttner tumor oten shows difuse involvement of
the salivary gland with heterogeneous echogenicity, dilated ducts,
calculi, and prominent intraglandular vessels. Focal salivary gland
lesions show hypoechoic heterogeneous regions with a radial
branching vascular pattern demonstrated by Doppler. 36
Kimura disease is a rare, possibly autoimmune inlammatory
disorder with slow-growing painless sot tissue masses frequently
in the subcutaneous tissues over the parotid, periauricular, and
submandibular regions. 37,38 here can be contiguous extension
of the lesions into the parotid gland. 39 hese lesions are frequently
described in adolescent and young adult Asian males. 37 here
may be associated intraparotid, submental, and submandibular
lymphadenopathy, with normal node morphology. On sonography
the sot tissue masses are found to be heterogeneous hypoechoic
centrally with echogenic hypervascular rim. Lymph nodes show
exaggerated hilar and capsular vascularity. 37,38
Human immunodeiciency virus (HIV) infection can afect
all salivary glands, but primarily the parotid. he patient may
demonstrate bilateral parotid swelling and lung disease from
lymphocytic interstitial pneumonitis. 15 Infection is characterized
by benign lymphoepithelial lesions, consisting of lymphoid
hyperplasia accompanied by an intranodal cyst lined by epithelial
cells. 40,41 Prevalence of salivary gland abnormalities in pediatric
HIV can be as high as 58%, and they can be present even in the
absence of a history of parotid enlargement. 42 Bilateral cystic
enlargement of the parotid glands is a widely recognized cause
of parotid gland swelling in patients with HIV infection but can
be diicult to diferentiate from recurrent parotitis, Sjögren
syndrome, lymphoma, and Warthin tumor. 24,40 In 70% of patients,
on sonography an enlarged gland is noted containing small,
hypoechoic areas without acoustic enhancement and with thick
septations consistent with lymphoid iniltration 15,43,44 (Fig. 48.15).
In 30% there are large, anechoic areas consistent with lymphoepithelial
cysts replacing the gland. From 40% to 70% of HIV
patients have associated symmetrical cervical adenopathy and
enlarged adenoids. 45