Salivary gland inflammation, obstruction, or tumor — postprandial swelling (stone), duct pus (bacterial), bilateral parotitis (mumps), painless parotid mass (tumor).
Also known as: sialadenitis, sialolithiasis, salivary stones, parotitis, mumps, submandibular sialolith, salivary gland tumor, parotid tumor, pleomorphic adenoma, Warthin tumor
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. Salivary gland neoplasms are benign or malignant tumors, most often of the parotid; pleomorphic adenoma is the most common.
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. Salivary neoplasms: about 80% arise in the parotid and most are benign; pleomorphic adenoma is the most common (roughly 60%), usually in adults aged 30-60, more often women. The smaller the gland, the more likely a tumor is malignant (about 20-25% of parotid, 40-50% of submandibular, and most sublingual and minor salivary gland tumors).
Try two board-style Salivary Gland Disorders questions
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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. He has never smoked. 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?
APleomorphic adenoma
BParotid lipoma
CWarthin tumor
DAdenoid cystic carcinoma
EMucoepidermoid carcinoma
Reveal answer & full explanation
Correct answer: A — Pleomorphic adenoma
APleomorphic adenoma✓
BParotid lipoma
CWarthin tumor
DAdenoid cystic carcinoma
EMucoepidermoid carcinoma
Why Pleomorphic adenoma is correct
Pleomorphic adenoma is the most common salivary gland neoplasm, accounting for roughly 60-70% of parotid tumors (about 80% of benign ones).
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
Warthin tumor — Warthin tumor (papillary cystadenoma lymphomatosum) is the second most common benign parotid tumor; it is strongly associated with cigarette smoking (roughly 8-fold risk), peaks at age 60-70, typically presents as a soft or fluctuant, often cystic mass in the parotid tail, and is bilateral or multifocal in about 10-15%; a firm mass in a 45-year-old who has never smoked points away from it, and it is far less common than pleomorphic adenoma.
Mucoepidermoid carcinoma — Mucoepidermoid carcinoma is the most common malignant salivary tumor; low-grade tumors can mimic a painless benign mass, while high-grade tumors cause pain, fixation, or facial nerve palsy; it is far less common than pleomorphic adenoma in this presentation.
Adenoid cystic carcinoma — Adenoid cystic carcinoma is malignant, characterized by perineural invasion, pain, and facial nerve palsy.
Parotid lipoma — the painless, slowly enlarging, mobile mass fits the textbook lipoma description, but lipomas feel soft and compressible and are uncommon in the parotid; a firm, well-circumscribed nodule in the superficial lobe of a middle-aged adult is most likely pleomorphic adenoma.
Additional high-yield points
Facial nerve dysfunction, rapid growth, fixation, or lymphadenopathy should raise concern for malignancy.
Pleomorphic adenoma vs Warthin tumor, the two most common benign parotid tumors: pleomorphic adenoma is a firm, unilateral mass in middle-aged adults; Warthin tumor favors older smokers, is often soft or cystic, and may be bilateral or multifocal.
Question 2EENTMedium
A 58-year-old man underwent superficial parotidectomy six months ago for a benign pleomorphic adenoma. He now reports that whenever he eats, the skin overlying his surgical scar in front of the ear becomes flushed and sweats profusely. The symptoms began about 4 months postoperatively and occur with every meal. He denies facial weakness, pain, or salivary fistula. Examination reveals visible perspiration over the preauricular skin during a taste challenge. Which of the following is the most likely diagnosis?
ASialocele
BFrey syndrome
CRecurrent pleomorphic adenoma
DCrocodile tears syndrome
EGreat auricular nerve injury
Reveal answer & full explanation
Correct answer: B — Frey syndrome
ASialocele
BFrey syndrome✓
CRecurrent pleomorphic adenoma
DCrocodile tears syndrome
EGreat auricular nerve injury
Why Frey syndrome is correct
This patient has Frey syndrome (auriculotemporal or gustatory sweating syndrome), the most common long-term complication after parotid surgery for benign tumors such as pleomorphic adenoma.
It occurs when severed parasympathetic secretomotor fibers originally destined for the parotid gland aberrantly regenerate and reinnervate the sweat glands and cutaneous vessels of the overlying skin.
As a result, gustatory stimuli trigger sweating and flushing instead of salivation.
Diagnosis is clinical and can be confirmed with the Minor starch-iodine test.
Why the others are wrong
Sialocele — an early postoperative fluid collection of saliva, presenting as a fluctuant swelling within weeks of surgery, not a chronic gustatory phenomenon (confused-with early complication).
Recurrent pleomorphic adenoma — would present as a palpable mass at the surgical site, not autonomic skin symptoms (anchoring on prior tumor).
Crocodile tears syndrome — gustatory lacrimation from aberrant regeneration of facial nerve salivary fibers to the lacrimal gland, usually during recovery from a proximal facial nerve injury such as Bell palsy; it causes tearing with meals, not sweating and flushing of the preauricular skin (confused-with aberrant-regeneration syndrome).
Great auricular nerve injury — a frequent sensory complication of parotidectomy that leaves the earlobe and preauricular skin numb, but it produces sensory loss rather than meal-triggered sweating and flushing of the overlying skin (confused-with other parotidectomy complication).
Additional high-yield points
Treatment options include topical antiperspirants (aluminum chloride), topical anticholinergics (glycopyrrolate), or botulinum toxin injections.
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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 (chronic sialadenitis; also salivary tumors, especially mucoepidermoid carcinoma)
Mumps virus exposure in unvaccinated patients
Chronic ductal stricture or prior duct injury
Cigarette smoking (Warthin tumor)
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. Neoplasms: the facial nerve (CN VII) divides the parotid into superficial and deep lobes. Pleomorphic adenoma (benign mixed tumor) has an incomplete capsule with finger-like projections (pseudopods) that are left behind if the tumor is shelled out, and a long-standing tumor can turn malignant (carcinoma ex pleomorphic adenoma). Warthin tumor is a benign cystic, lymphoid-rich tumor strongly linked to smoking.
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
Salivary neoplasm: usually a painless mass in front of the ear or at the angle of the jaw, slowly enlarging over months to years, unrelated to meals and without fever
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
Pleomorphic adenoma: firm, mobile, well-circumscribed parotid mass (usually superficial lobe) with normal facial nerve function; Warthin tumor: softer, often cystic parotid-tail mass in an older smoker, sometimes bilateral
Malignancy red flags: pain, rapid growth, fixation to skin or deep tissue, facial nerve (CN VII) palsy, cervical lymphadenopathy
Classic findings
Postprandial gland swelling that resolves over hours (stone), pus from Stensen duct (bacterial parotitis), bilateral parotid swelling in an unvaccinated patient (mumps), painless firm mobile parotid mass with normal facial nerve function (pleomorphic adenoma).
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 RT-PCR of a buccal (parotid duct) swab, the preferred test, or by a significant rise in paired IgG titers; IgM supports the diagnosis but is not confirmatory and is often negative in vaccinated patients. Stones are identified on ultrasound or CT. Bacterial sialadenitis is diagnosed by exam plus expression of pus. Salivary tumors are typed by FNA (pleomorphic adenoma shows epithelial and myoepithelial cells in a chondromyxoid stroma) and confirmed on the surgical specimen.
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
Contrast MRI — for a salivary mass that is deep, fixed, or suspicious for malignancy; defines deep-lobe extension and perineural spread
Ultrasound-guided FNA for any persistent salivary mass (core needle biopsy if nondiagnostic); avoid open incisional biopsy, which risks tumor spillage and facial nerve injury
Diagnostic algorithm
Feature
Sialolithiasis
Bacterial sialadenitis
Mumps parotitis
Pleomorphic adenoma
Typical onset
Recurrent, meal-triggered
Acute, hours to days
Acute, days; prodrome
Painless, slow growth over months to years
Gland involved
Submandibular > parotid
Parotid > submandibular
Parotid (often bilateral)
Parotid, usually superficial lobe
Fever / systemic
No
Yes
Low-grade; malaise
No
Pus from duct
No
Yes (key finding)
No (clear saliva)
No
Lateralization
Unilateral
Unilateral
Bilateral in 70%
Unilateral, solitary
First imaging step
Ultrasound or CT
Ultrasound
Clinical; PCR / IgM
Ultrasound (MRI if deep), then FNA
Treatment
Hydration, sialagogues, sialendoscopy
Antibiotics, hydration, massage
Supportive only
Superficial parotidectomy sparing CN VII; never enucleate
Differentiating the three common obstructive and inflammatory salivary presentations from the most common salivary tumor.
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
Pleomorphic adenoma: superficial (or partial) parotidectomy that removes the tumor with a cuff of normal gland while identifying and preserving the facial nerve (submandibular tumors: gland excision); never enucleate, because retained pseudopods cause recurrence
Salivary gland malignancy: parotidectomy (total if the deep lobe is involved) preserving CN VII unless directly invaded, neck dissection for nodal, high-grade, or advanced (T3-T4) disease, and postoperative radiation for high-grade or advanced tumors, positive margins, perineural invasion, or nodal metastases
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
Warthin tumor confirmed by FNA: observation is acceptable in older or high-surgical-risk patients; excise if it grows, causes symptoms, or the diagnosis is uncertain
Complications
Abscess formation requiring drainage
Recurrent obstruction with progressive gland atrophy and xerostomia
Spread of infection into the parapharyngeal or masticator space
After parotidectomy: Frey syndrome (sweating and flushing of the cheek with meals as cut parasympathetic fibers regrow into sweat glands) and earlobe numbness from great auricular nerve sacrifice
Pleomorphic adenoma: multinodular recurrence after enucleation or capsule rupture; malignant transformation (carcinoma ex pleomorphic adenoma), suspected when a long-standing mass suddenly grows
PANCE pearls
Postprandial unilateral gland swelling is sialolithiasis until proven otherwise; ultrasound is the first imaging step.
Submandibular stones predominate because Wharton duct travels uphill against gravity and carries mucin-rich saliva.
Always express the duct orifice — pus confirms bacterial sialadenitis and provides culture material.
Bilateral parotitis in an unvaccinated patient is mumps until proven otherwise; report to public health.
A persistent salivary mass or facial nerve weakness mandates imaging and FNA to exclude malignancy.
A painless, firm, mobile parotid mass in a middle-aged adult is most likely pleomorphic adenoma, the most common salivary tumor; an older smoker with a soft, sometimes bilateral parotid-tail mass suggests Warthin tumor.
Pain, rapid growth, fixation, facial nerve palsy, or neck nodes signal malignancy: mucoepidermoid carcinoma is the most common salivary cancer, and adenoid cystic carcinoma spreads along nerves (perineural invasion). The smaller the gland, the more likely a tumor is malignant.
Never enucleate a pleomorphic adenoma (retained pseudopods cause recurrence); superficial parotidectomy with facial nerve preservation is standard, and Frey syndrome (gustatory sweating) is the classic late complication.
References
AAO-HNS — American Academy of Otolaryngology-Head and Neck Surgery clinical resources on salivary gland disorders
CDC — Centers for Disease Control and Prevention: Mumps for Healthcare Providers and ACIP recommendations for MMR
StatPearls — Al Ghabra Y, Goldin J, Pandey S. Parotitis. StatPearls Publishing, NCBI Bookshelf NBK560735.
ASCO 2021 — Geiger JL et al. Management of Salivary Gland Malignancy: ASCO Guideline. J Clin Oncol 2021;39:1909-1941.
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