Chapter 31: The Salivary Glands

DEVELOPMENTAL ABNORMALITIES

The most common developmental salivary gland disorder is salivary tissue in an ectopic location such as the nasopharynx or middle ear (salivary gland choristoma). Other potential developmental disorders include aplasia/agenesis, duplication, and cysts. Salivary gland ducts can be atretic, imperforate, ectatic, or duplicated.

Salivary gland agenesis is a rare anomaly. Lack of salivary gland development can be complete, or (more commonly) involve a single gland. There are various potential associated anomalies, such as absence of the lacrimal puncta. This disorder usually occurs with an autosomal dominant pattern of inheritance. Affected children suffer severe dryness of the mouth and are prone to secondary dental abnormalities.¹

Mandibulofacial dysostosis syndrome includes agenesis or hypoplasia of the parotid glands in conjunction with masseter muscle agenesis/hypoplasia, cleft palate, and microstomia. Other facial bone deformities also occur in these children. Mandibulofacial dysostosis syndrome has an autosomal dominant pattern of inheritance. The anomalies in this syndrome predominantly involve derivatives of the first and second branchial arches.

Parotid aplasia and ectopic salivary gland tissue can occur in the various oculo-auriculo-vertebral syndromes such as Goldenhar syndrome and hemifacial microsomia (see Figure 26-21 in Chapter 26).²

Lacrimo-auriculo-dento-digital syndrome is a rare autosomal dominant ectodermal dysplasia that includes aplastic/hypoplastic salivary and lacrimal glands/ducts, cup-shaped ears, defective hearing, hypodontia and enamel hypoplasia, and distal limb anomalies.

INFECTION, INFLAMMATION (SIALADENITIS)

Viral

Acute viral infections of the salivary glands result in painful selling that is often bilateral. Acute viral sialadenitis due to mumps is the most common cause of salivary gland enlargement in children. Other viral pathogens include cytomegalovirus, influenza virus, and coxsackievirus. Diagnostic imaging evaluations are usually not required for these children unless there is an unusual clinical presentation or evidence of a complication. Cross-sectional imaging shows nonspecific salivary gland enlargement. On sonography, the edematous gland is hypoechoic. Color Doppler images frequently show prominent vascularity in the gland. There is usually an abnormal hyperintense character in T2-weighted MR sequences.³

Salivary gland enlargement is common in children with HIV infection. The gland enlargement is usually due to infiltration with CD8-positive lymphocytes. Lymphoepithelial cysts are less common than in adults.

Bacterial

Most suppurative infections of the salivary glands are due to Staphylococcus aureus, Streptococcus viridans, Streptococcus pneumoniae, or anaerobic bacteria. Children with these infections experience a rapid onset of symptoms that include pain, swelling, and redness. Either the parotid or submandibular glands may be affected; lingual gland involvement is rare. Acute bacterial sialadenitis occurs with an increased frequency in premature newborns, as well as chronically ill and dehydrated older children. Sonography and CT are sometimes useful for these children to confirm inflammation of the gland and to identify an abscess. The risk of an abscess is increased in patients with excretory duct obstruction (e.g., ...