Inflammation or obstruction of salivary glands — postprandial swelling (stone), tender swollen gland with pus (bacterial), bilateral parotitis (mumps).
Also known as: sialadenitis, sialolithiasis, salivary stones, parotitis, mumps, submandibular sialolith
Overview
A group of conditions involving the major salivary glands (parotid, submandibular, sublingual). Sialolithiasis is the formation of calculi within a salivary duct. Sialadenitis is inflammation of a salivary gland, which may be acute bacterial, chronic, viral (parotitis from mumps and other viruses), or autoimmune.
Epidemiology
Sialolithiasis: most common cause of salivary obstruction; 80% involve the submandibular (Wharton) duct because of its long, upward course and viscous mucinous secretion. Acute bacterial sialadenitis: most often parotid; affects dehydrated, postoperative, or elderly patients. Mumps parotitis: now uncommon in vaccinated populations but resurgent in outbreaks.
Try two board-style Salivary Gland Disorders questions
Real questions from the FirstPassPA bank, with the full explanation. Pick an answer — no signup, no email.
Question 1EENTMedium
A 45-year-old man presents with a slowly enlarging, painless mass in front of his right ear over the past 18 months. He denies facial weakness, numbness, or skin changes. On examination, there is a firm, mobile, well-circumscribed 2.5 cm nodule in the superficial lobe of the right parotid gland. The overlying skin is normal, and cranial nerve VII function is intact bilaterally. Cervical lymph nodes are not enlarged. Which of the following is the most likely diagnosis?
AWarthin tumor
BPleomorphic adenoma
CMucoepidermoid carcinoma
DAdenoid cystic carcinoma
Reveal answer & full explanation
Correct answer: B — Pleomorphic adenoma
AWarthin tumor
BPleomorphic adenoma✓
CMucoepidermoid carcinoma
DAdenoid cystic carcinoma
Why Pleomorphic adenoma is correct
Pleomorphic adenoma is the most common benign salivary gland neoplasm, accounting for roughly 80% of parotid tumors.
It typically presents in middle-aged adults as a slowly growing, painless, firm, mobile mass in the superficial parotid lobe with intact facial nerve function.
The tumor arises from a mix of epithelial and myoepithelial cells with a chondromyxoid stroma.
Diagnosis is supported by ultrasound or MRI and confirmed with fine-needle aspiration; superficial parotidectomy is curative, with care to preserve CN VII.
Why the others are wrong
A) Warthin tumor — Warthin tumor (papillary cystadenoma lymphomatosum) also presents as a benign parotid mass but typically occurs in older male smokers and is often bilateral or multifocal.
C) Mucoepidermoid carcinoma — Mucoepidermoid carcinoma is the most common malignant salivary tumor and often presents with facial nerve involvement, pain, or fixation.
D) Adenoid cystic carcinoma — Adenoid cystic carcinoma is malignant, characterized by perineural invasion, pain, and facial nerve palsy.
Additional high-yield points
Facial nerve dysfunction, rapid growth, fixation, or lymphadenopathy should raise concern for malignancy.
Question 2EENTEasy
A 44-year-old man reports a 3-week history of recurrent painful swelling under his right jaw. The swelling appears within minutes of starting a meal and gradually subsides over the next few hours. He has no fever and feels well between episodes. On bimanual palpation of the floor of the mouth, a firm tender nodule is felt along the right submandibular duct, and only scant clear saliva is expressed from the duct orifice when the gland is massaged. Which of the following is the most likely diagnosis?
AReactive cervical lymphadenitis
BSubmandibular gland neoplasm
CSubmandibular sialolithiasis
DAcute bacterial sialadenitis
Reveal answer & full explanation
Correct answer: C — Submandibular sialolithiasis
AReactive cervical lymphadenitis
BSubmandibular gland neoplasm
CSubmandibular sialolithiasis✓
DAcute bacterial sialadenitis
Why Submandibular sialolithiasis is correct
Recurrent unilateral gland swelling that begins with eating and resolves over hours is the textbook presentation of a salivary duct stone: saliva backs up behind the obstructing calculus during meal-stimulated flow, then drains once stimulation ends.
A palpable stone along the duct on bimanual floor-of-mouth palpation with little saliva from the orifice confirms obstruction. About 80% of stones lodge in the submandibular (Wharton) duct because it runs uphill against gravity and carries viscous, mucin-rich saliva.
Diagnosis is clinical and supported by imaging; ultrasound is the first imaging step, with non-contrast CT highly sensitive for calculi.
Why the others are wrong
Acute bacterial sialadenitis: rapidly progressive, constantly painful swelling of a single gland with fever, an indurated erythematous gland, and frank pus expressible from the duct; this patient is afebrile, well between meals, and produces no pus.
Submandibular gland neoplasm: a salivary tumor such as pleomorphic adenoma presents as a painless, slowly enlarging mass, not as intermittent meal-triggered swelling that fully resolves.
Reactive cervical lymphadenitis: produces a tender, movable node in the neck rather than swelling within the gland itself, and is not provoked by eating; ultrasound localizes the abnormality to a lymph node rather than the duct or gland.
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Anticholinergic, antihistamine, diuretic, or psychotropic medications
Poor oral hygiene
Sjogren syndrome and other autoimmune disease (chronic sialadenitis)
Head and neck radiation
Mumps virus exposure in unvaccinated patients
Chronic ductal stricture or prior duct injury
Pathophysiology
Sialolithiasis: stasis of saliva and supersaturation of calcium phosphate within the duct forms a calculus, leading to ductal obstruction, glandular swelling with meals, and secondary infection. Acute bacterial sialadenitis: retrograde ascent of oral flora (Staphylococcus aureus, streptococci, anaerobes) through the duct in a setting of decreased flow. Mumps: lymphotropic paramyxovirus causes acinar inflammation, often bilateral; orchitis, oophoritis, and meningoencephalitis are extraglandular complications.
Clinical presentation
Symptoms
Sialolithiasis: recurrent unilateral gland swelling and pain triggered by meals or the sight of food; symptoms resolve over hours
Acute bacterial sialadenitis: rapidly progressive painful swelling of a single gland, fever, malaise, purulent discharge from the duct on massage
Mumps parotitis: bilateral parotid swelling, low-grade fever, malaise, headache; complications include orchitis (in 20-30% of postpubertal males), meningoencephalitis, deafness
Chronic sialadenitis: recurrent episodes of swelling with reduced salivary flow
Signs / physical exam
Sialolithiasis: bimanual palpation of the floor of the mouth or along the duct may reveal a palpable stone; little or no saliva from the duct orifice on gland massage
Bacterial sialadenitis: tender, erythematous, indurated gland; pus expressible from the duct orifice (Stensen for parotid, Wharton for submandibular)
Mumps: bilateral parotid swelling that obliterates the angle of the mandible; reddened, slightly edematous duct orifice (Stensen) without pus
Facial nerve weakness suggests malignancy or severe deep infection
Classic findings
Postprandial gland swelling that resolves over hours (stone), pus from Stensen duct (bacterial parotitis), bilateral parotid swelling in an unvaccinated patient (mumps).
Differential diagnosis
Lymphadenitis — Tender movable node in the neck, not within glandular tissue; ultrasound clarifies anatomy
Diagnosis is clinical, supported by imaging. Mumps is confirmed by IgM seroconversion or PCR. Stones are identified on ultrasound or CT. Bacterial sialadenitis is diagnosed by exam plus expression of pus.
Labs
CBC with differential, basic metabolic panel for dehydration
Pus culture from duct orifice if present
Mumps IgM, IgG, and PCR (buccal swab) when mumps suspected
Autoimmune panel (ANA, anti-Ro/SS-A, anti-La/SS-B, IgG4) for chronic disease
Imaging
Ultrasound — first-line for any salivary mass or suspected obstruction; identifies stones, abscess, and gland architecture
Non-contrast CT — excellent sensitivity for calculi; preferred when ultrasound non-diagnostic
Sialography or MR sialography — for ductal strictures or recurrent obstruction without visible stone
FNA biopsy for any persistent mass
Diagnostic algorithm
Feature
Sialolithiasis
Bacterial sialadenitis
Mumps parotitis
Typical onset
Recurrent, meal-triggered
Acute, hours to days
Acute, days; prodrome
Gland involved
Submandibular > parotid
Parotid > submandibular
Parotid (often bilateral)
Fever / systemic
No
Yes
Low-grade; malaise
Pus from duct
No
Yes (key finding)
No (clear saliva)
Lateralization
Unilateral
Unilateral
Bilateral in 70%
First imaging step
Ultrasound or CT
Ultrasound
Clinical; PCR / IgM
Treatment
Hydration, sialagogues, sialendoscopy
Antibiotics, hydration, massage
Supportive only
Differentiating the three common salivary gland presentations.
Treatment
First-line
Hydration, warm compresses, gland massage, sialagogues (sour candies, lemon drops), and good oral hygiene for any obstructive or inflammatory salivary disease
Sialolithiasis: conservative measures plus NSAIDs; small stones near the duct orifice can often be milked out; persistent or proximal stones require sialendoscopy, intraoral stone removal, or gland excision
Acute bacterial sialadenitis: empiric oral antibiotic for outpatient mild disease — amoxicillin-clavulanate or clindamycin; severe cases require IV ampicillin-sulbactam or, if MRSA suspected, vancomycin plus a beta-lactam
Mumps: supportive care only — hydration, analgesia, antipyretics, isolation; report to public health
Second-line / adjunct
Sialendoscopy for ductal stricture or chronic recurrent disease
Surgical excision (submandibulectomy or parotidectomy) for recurrent disease unresponsive to less invasive measures or for chronic gland atrophy
Treatment of underlying autoimmune disease (steroids and disease-modifying therapy for IgG4 disease, Sjogren management)
Vaccination (MMR) for prevention of mumps; postexposure vaccination of contacts during outbreaks
Complications
Abscess formation requiring drainage
Recurrent obstruction with progressive gland atrophy and xerostomia
Spread of infection into the parapharyngeal or masticator space
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