Summary![toggle arrow icon](https://manus-media.amboss.com/icons/chevron_up.svg)
Diseases of the salivary glands (e.g., parotid, submandibular, and sublingual glands) include sialadenosis, sialadenitis, and sialolithiasis. Sialadenosis and sialadenitis primarily affect the parotid gland. Sialadenosis is the recurrent, painless, and often bilateral swelling of salivary glands without inflammation; treatment is focused on management of the underlying disease. Sialadenitis is the painful acute inflammation of salivary glands and is generally categorized according to etiology. Acute suppurative sialadenitis is caused by bacterial infection, while nonsuppurative sialadenitis is due to viral infection (e.g., mumps) or chronic conditions (e.g., salivary stasis, autoimmune disorders). Management includes supportive care (e.g., pain control, sialagogues) and treatment of the underlying cause. Sialolithiasis is the formation of stones within the salivary ducts, which may cause swelling and pain associated with eating. Treatment can be conservative (e.g., pain control, sialogogues) or surgical (stone removal).
Salivary gland tumors manifest mainly in the parotid. Painless and progressive swelling of the gland is the cardinal symptom of benign as well as malignant tumors, while facial palsy is considered a criterion for malignancy. Generally, the smaller the gland, the greater the chance that the tumor is malignant. Clinical examination and ultrasound play the biggest role in diagnosis. For all parotid tumors, the preferred treatment is parotidectomy with retention of the facial nerve. A resection of the facial nerve is indicated only if it is infiltrated by the tumor. Postoperative radiation therapy may benefit patients with malignant tumors.
Overview![toggle arrow icon](https://manus-media.amboss.com/icons/chevron_up.svg)
Overview of salivary gland diseases [1][2] | |||||
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Features | Acute suppurative sialadenitis | Viral sialadenitis (e.g., mumps) | Sialolithiasis | Sialadenosis | Tumors of the salivary glands |
Most common location | |||||
Swelling |
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Pain |
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Fever |
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Other findings |
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Sialadenitis![toggle arrow icon](https://manus-media.amboss.com/icons/chevron_up.svg)
Acute suppurative sialadenitis [1][3][4]
- Definition: acute inflammation of the salivary glands due to bacterial infection
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Etiology: retrograde bacterial contamination from the mouth into the salivary ducts [3]
- Most commonly Staphylococcus aureus
- Less often viridans streptococci, Haemophilus influenzae, or polymicrobial
- Location: most often the parotid gland [1]
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Risk factors
- Obstructive factors (e.g., sialolithiasis)
- Autoimmune disorders
- Hospitalized or postoperative patients
- Salivary stasis (e.g., dehydration, anticholinergic medications)
- Poor oral hygiene
- Diabetes mellitus
- Hypothyroidism
- Renal failure
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Clinical features
- Acute onset
- Unilateral painful swelling and erythema of the salivary gland and affected area
- Purulent discharge expressed from salivary duct orifice
- Systemic symptoms (e.g., fever, chills)
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Diagnostics: clinical diagnosis [5]
- Gram stain and culture of purulent discharge
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Imaging (e.g., ultrasound, CT) is indicated for the following:
- Concern for complications (e.g., abscess)
- Suspected sialolithiasis
- Palpable mass
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Treatment [5]
- Symptomatic management of salivary gland disorders, e.g.:
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Antibiotic therapy
- Amoxicillin/clavulanate; (off-label) OR clindamycin (off-label) [4]
- If patients cannot tolerate oral intake or have severe infection: ampicillin/sulbactam (off-label) [3]
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Surgery
- Abscess: incision and drainage
- Salivary stone: stone extraction (e.g., via sialoendoscopy, ductal dilation)
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Complications
- Abscess (e.g., parapharyngeal, intraglandular)
- Ludwig angina
- Facial nerve paralysis
Viral sialadenitis [1][3][4]
- Definition: acute nonsuppurative inflammation of the salivary glands due to viral infection
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Etiology
- Mumps (most common)
- HIV
- Hepatitis C
- Influenza
- Cytomegalovirus
- Clinical features
- Diagnostics: based on suspected underlying cause (e.g., diagnostics for mumps, HIV testing)
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Treatment
- Symptomatic management of salivary gland disorders
- Manage the underlying cause (e.g., treatment for mumps, management of HIV).
Chronic sialadenitis [1][3][4]
- Definition: recurrent episodes of pain and inflammation of the salivary glands
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Etiology
- Salivary stasis (e.g., sialolithiasis)
- Autoimmune disorders (e.g., Sjogren syndrome)
- Neoplasms
- Bacterial infection
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Clinical features
- Recurrent episodes of pain and swelling
- Clinical features of the underlying cause (e.g., sialolithiasis, Sjogren syndrome)
- Diagnostics: based on suspected underlying cause (e.g., diagnostics for Sjogren syndrome)
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Treatment
- Symptomatic management of salivary gland disorders
- Manage the underlying cause.
- If conservative management is unsuccessful, refer patients to otolaryngology for possible surgical intervention (e.g., sialoendoscopy, ductal ligation, gland excision).
Sialolithiasis![toggle arrow icon](https://manus-media.amboss.com/icons/chevron_up.svg)
Sialolithiasis is the formation of stones within the salivary ductal system.
Etiology [4]
- Unclear; thought to be due to calcification of a nidus within the ductal system
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Risk factors include:
- Dehydration
- Smoking
- Medication effects (e.g., diuretics, anticholinergics)
- Gout
- Trauma
- Chronic periodontal disease
Clinical features [4]
- Location
- Submandibular gland (80–95% of cases) [4]
- Less commonly parotid or sublingual glands
- Recurrent pain before and after eating
- Swelling of the affected gland
- Palpable or visible stone
Diagnostics [4][6]
- Clinical diagnosis
- Imaging may be used to confirm diagnosis or evaluate for alternative etiologies or complications.
- CT without contrast (first-line): high sensitivity for detecting salivary stones [4]
- Ultrasound: detects most stones ≥ 2 mm
- Sialography (e.g., magnetic resonance sialography, conventional sialography)
- Sialoendoscopy
Treatment [4][6]
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Symptomatic management of salivary gland disorders
- NSAIDs for pain relief
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Stimulation of salivary flow
- Sialogogues
- Glandular massage
- Warm compresses
- Oral and/or IV fluid therapy
- Oral hygiene
- Palpable stone: Attempt to massage the gland to remove the stone.
- For signs of infection, see “Treatment” in “Acute suppurative sialadenitis.”
- Indications for otolaryngology referral include: [6]
- Symptoms lasting more than a few days
- Stones within the gland, in the proximal duct, or > 5 mm
- Recurrent sialolithiasis
- Acute suppurative sialadenitis and no improvement with antibiotics
- Interventions: sialoendoscopy; , laser lithotripsy, transoral stone removal, or sialadenectomy
Complications [3]
- Acute suppurative sialadenitis
- Chronic sialadenitis
- Salivary duct stricture
- Ductal ectasia
Sialadenosis![toggle arrow icon](https://manus-media.amboss.com/icons/chevron_up.svg)
- Definition: recurrent, noninflammatory swelling of the salivary glands
- Location: : most often the parotid gland
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Etiology
- Endocrine: particularly diabetes mellitus
- Dystrophic sialadenosis: alcohol use disorder, malnutrition, or eating disorders (e.g., bulimia) [7]
- Medications: e.g., clonidine
- Symptoms: painless swelling (usually bilateral)
- Treatment: treatment of underlying disease
Ranula![toggle arrow icon](https://manus-media.amboss.com/icons/chevron_up.svg)
- Definition: retention cyst arising in the sublingual gland
- Epidemiology: [8]
- Etiology: unclear
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Clinical features
- Translucent blue swelling below the tongue
- Can cause problems swallowing and speaking
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Treatment
- Extirpation of the ranula, including the sublingual gland
- Marsupialization
Benign tumors![toggle arrow icon](https://manus-media.amboss.com/icons/chevron_up.svg)
Most salivary gland tumors are benign.
Pleomorphic adenoma (benign mixed tumor)
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Epidemiology
- Sex: ♀ > ♂
- Peak incidence: 40–60 years
- Most common salivary gland tumor (accounts for 85% of benign salivary gland tumors)
- Etiology: ionizing radiation, environmental/occupational exposure (e.g., rubber manufacturing, cosmetologists, nickel compound exposure) [9]
- Location: usually the parotid gland (∼ 80% of cases)
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Clinical features
- Gradual and painless unilateral swelling of the gland
- Robust, movable tumor
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Diagnostics
- Ultrasound: diagnostic method of choice in salivary gland tumors
- MRI (T2-weighted image): sharply limited, lobulated hyperintense mass [10]
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Histology
- Mixed cellular constitution with myoepithelial cells and chondroid tissue
- Cytokeratin is expressed immunohistochemically
- Complications: Malignant transformation may occur (∼ 5% of cases).
- Treatment: : Best treatment is superficial parotidectomy to prevent recurrence. [11]
- Prognosis
Other types of benign salivary gland tumors (monomorphic adenomas)
These benign salivary gland tumors fall under the umbrella term "monomorphic adenoma" because they usually originate in only one type of cell – as opposed to the pleomorphic adenomas, which consist of both epithelial and myoepithelial cells.
Warthin tumor (papillary cystadenoma lymphomatosum)
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Epidemiology
- Sex: ♂ >> ♀
- Peak incidence: 60–80 years
- 2nd most common benign salivary gland tumor (accounting for 10% of benign cases) [12]
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Etiology
- Ionizing radiation
- Smoking
- Location: : most often the parotid gland (10% bilateral, 10% multifocal)
- Clinical features: gradual and painless unilateral swelling of the parotid
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Diagnostics
- Ultrasound: diagnostic method of choice in salivary gland tumors
- MRI
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Histology
- Cystic structure
- Germinal centers
- Treatment: complete extirpation of the tumor with preservation of facial nerve
- Complications: rarely malignant transformation
WARning! Smoking makes GERMs more resilient.
Rare histologic subtypes
- Oncocytoma (∼ 2% of cases)
- Basal cell adenoma (∼ 1–2% of cases)
- Myoepithelioma (∼ 1% of cases)
Malignant tumors![toggle arrow icon](https://manus-media.amboss.com/icons/chevron_up.svg)
Malignant salivary gland tumors are referred to collectively because of their many etiological, epidemiological, and pathological similarities.
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Location
- Most common: parotid gland → parotid carcinoma
- Less common locations
- Submandibular and sublingual glands: Neoplasms in these locations are less common compared to those in the parotid gland, but they are more frequently malignant (∼ 45% of submandibular and 70–90% of sublingual tumors).
- Minor salivary glands (gums and the base of the mouth): Most tumors are malignant.
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Etiology
- Ionizing radiation
- Viral infection (e.g., HIV may be implicated )
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Symptoms
- Insidious onset
- Painless submucosal swelling or mucosal ulceration (palate, buccal mucosa, lips)
- In some cases, clinical symptoms arise if the neighboring structures are infiltrated (e.g., facial palsy caused by parotid carcinomas).
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Diagnostics
- Ultrasound of the head and neck (to determine location and size of mass); with or without biopsy (definitive diagnosis)
- Contrast enhanced CT/MRI of head and neck: useful as preoperative workup to determine location, size, and extension of the lesion
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Pathology
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Subtypes
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Mucoepidermoid carcinoma
- Most common malignant salivary gland tumor
- Involves squamous and mucinous cells, both of which arise from excretory stem cells [13]
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Adenoid cystic carcinoma (obsolete term: cylindroma)
- Growth along nerve sheaths
- Cribriform or tubular growth pattern
- Very slow but dangerous infiltrative growth
- Acinic cell carcinoma
- Adenocarcinoma
- Metastases of other malignant tumors in head and neck
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Mucoepidermoid carcinoma
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Routes of metastasis
- Initially lymphogenic in local lymph nodes
- Later hematogenic metastasis, particularly in the lungs
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Subtypes
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Treatment
- Curative
- Parotidectomy (superficial or total), if possible, with preservation of the facial nerve
- +/- Neck dissection and/or adjuvant radiotherapy for extensive or higher grade tumors
- Palliative: chemotherapy
- Curative
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Complications of a parotidectomy
- Facial nerve injury (most common early complication)
- Hematoma
- Salivary fistula
- Frey syndrome: gustatory sweating
- Crocodile tears (gustatory hyperlacrimation): Regenerating parasympathetic gustatory fibers attach to the lacrimal gland.
Submandibular gland tumors are less common but more frequently malignant than parotid tumors. Generally, the smaller the gland, the higher the risk a tumor is malignant!
References:[14][15]