Chia Haddad and Devraj Basu

Salivary glands are distributed throughout the head and neck and can be divided into major and minor glands. The major salivary glands include the paired parotid, submandibular, and sublingual glands. The minor salivary glands consist of over 500 much smaller submucosal structures distributed throughout the upper aerodigestive tract.

Disorders of the salivary glands can manifest with a variety of symptoms. Rapid onset of pain, diffuse enlargement, and tenderness of major salivary glands, either unilateral or bilateral, is typically associated with acute infectious processes. These conditions may be accompanied by systemic symptoms such as fever and fatigue. However, a painful, swollen gland may also be seen with a variety of other conditions. An isolated, persistent salivary gland mass is more suggestive of neoplasm and often presents without other symptoms. When this is associated with pain or facial paralysis, it is strongly suggestive of malignancy. Sialadenosis is a noninflammatory, nonneoplastic enlargement of a salivary gland that is generally asymptomatic. Xerostomia is dry mouth due to a lack of saliva production. Sialorrhea or ptyalism is the excessive production or impaired swallowing of saliva, often leading to drooling. Halitosis is oral malodor (bad breath), a small subset of which is secondary to salivary gland disturbance.

Presenting Symptom

Painful Swelling of a Major Salivary Gland

Viral infection

Mumps (systemic paramyxovirus): Remains an important cause of diffuse painful parotid enlargement despite a precipitous decline in cases since the introduction of vaccination in 1964. The virus has an incubation time of 2 to 3 weeks, after which diffuse pain and swelling can occur in one or both parotid glands. Often there will be a prodrome of fever, malaise, and myalgia. Major associated complications include sudden sensorineural hearing loss, meningitis, encephalitis, orchitis/oophoritis, and pancreatitis. Chronic obstructive sialadenitis may also develop as a sequela of the acute infection.

Cytomegalovirus, coxsackievirus, echovirus, and influenza A: Can all cause similar syndromes that include salivary gland swelling mimicking mumps

Acute suppurative sialadenitis: Most commonly involves the parotid gland but also frequently affects the submandibular gland. It can be bilateral in up to 20% of cases. Patients will present with pain, tenderness, and swelling, and may also complain of increased pain with eating. Often purulence can be expressed from the duct orifice with gland massage and milking the duct, and appearance of pus with this maneuver is considered diagnostic. Staphylococcus aureus is the most common pathogen, although other bacteria such as Streptococcus pneumoniae, Escherichia coli, and Haemophilus influenzae can be etiologies. Salivary stasis is thought to be the major predisposing factor. Stasis can be caused by obstruction secondary to a salivary stone or stricture, medications that decrease saliva production, or dehydration. It often appears in a postoperative setting and in elderly, debilitated patients. Infections can be complicated by abscess formation, which requires aspiration or open surgical drainage.

Chronic sialadenitis: Can be a sequela of recurrent acute infection, other inflammatory disease, partial plugging of salivary ducts with calculi, and/or ductal stricture. These changes result in decreased secretion and overall stasis. Chronic sialadenitis is most common in the parotid gland. Patients typically describe a mildly painful recurrent swelling that is worsened by eating, and they may also complain of xerostomia. Occasionally, another treatable anatomical cause may exist, such as an extractable stone or an isolated stricture that may be dilated.

Cat scratch disease: A self-limited disease caused by Bartonella henselae. Although this disease does not directly involve the salivary glands, it can present as acute painful swelling of intraparotid lymph nodes, though typically producing an ill-defined mass rather than diffuse gland enlargement. Some cases may mimic the symptoms of a malignant parotid neoplasm (see later discussion).

Primary salivary tuberculosis: Very rare. The disease is most often unilateral and involves the parotid gland.

Sialolithiasis (salivary calculi): Eighty percent of stones occur within the submandibular gland, with most of the remainder in the parotid gland. Patients will complain of recurrent pain and swelling of the involved gland, especially while eating. A calculus may be palpable within the duct, and most stones are identifiable on computed tomography. Secondary acute bacterial sialadenitis may develop as the presenting symptom. Other complications include ductal ectasia and/or stricture, predisposing to recurrent or chronic sialadenitis.

Noninfectious granulomatous disease

Sarcoidosis: Can manifest as diffuse salivary gland enlargement in up to 33% of cases. Uveoparotid fever is a syndromic manifestation of sarcoid characterized by the association of uveitis, parotid enlargement, and facial paralysis.

Benign neoplasms: These represent 75 to 80% of all parotid neoplasms, 50% of submandibular neoplasms, and < 40% of sublingual and minor salivary gland neoplasms. These lesions typically present with painless, gradual enlargement over time without facial nerve paralysis.