Diagnosis>Organ System>

PATHOGENS

• Staphylococcus spp., primarily Staphylococcus aureus [Sialoadenitis]

CLINICAL

• Parotid gland most commonly involved.
• Bilateral painless enlargement common in HIV population.
• Observe for skin changes, palpate gland (direct and bimanual), assess facial nerve function, intraoral exam (milk gland to express saliva, parapharyngeal space involvement) and assess for cervical lymphadenopathy. Bilateral vs unilateral gland swelling is an important feature.
• Signs suspicious for malignancy include skin changes, unilateral swelling, large cervical lymph nodes, tenderness, and facial nerve weakness.
• Character of fluid expressed from salivary duct (intraoral) should be noted, purulent discharge consistent with sialoadenitis.
• Can be associated with cervical lymphadenopathy. May be neoplastic or diffuse infiltrative lymphocytosis syndrome (DILS) secondary to massive CD8 cell lymphoproliferation.
• Lymphocytic infiltration causes destruction of acinar tissue leading to sialadenitis and xerostomia.

DIAGNOSIS

• Bilateral salivary gland enlargement: vitamin deficiency, malnutrition, bulimia, diabetes, hypothyroidism, obesity, malabsorption (pancreatic insufficiency), cirrhosis, anemia, Sjogrens syndrome (risk of non-Hodgkins lymphoma) and medications (ie antihypertensives, catecholamines, iodine-containing compounds).
• Neoplastic etiologies in HIV population include adenoid cystic carcinoma, non-Hodgkins lymphoma, Kaposis sarcoma and mucosa associated lymphoid tissue (MALT) lymphoma. Parotid most common salivary gland involved with lymphoma, sublingual gland is the least. Other neoplastic etiologies; Benign: pleomorphic adenoma, Warthin's tumor, oncocytoma, and monomorphic adenoma. Malignant: mucoepidermoid, acinic cell, adenocarcinoma, malignant mixed and squamous cell.
• Unilateral gland enlargement: Infectious: Acute sialoadenitis (typically S. aureus, also pneumococcus, dehydration is risk factor), abscess, mumps, granulomatous sialoadenitis, actinomycosis. Non-infectious: Sialolithiasis, branchial cleft cyst (type I), uveoparotid fever (syndrome of uveitis, parotitis and fever), retention cysts.
• Benign lymphoepithelial cyst: most common cause of parotid swelling in HIV+ pt. Originate from lymph nodes within the parotid gland. Represent lymphoid hyperplasia with dilated cystic ducts. 20% bilateral.
• Parotid pseudocysts: secondary to viral inflammation. May appear before patient HIV seroconverts. Usually multiple, multiloculated and bilateral in 80% of cases.

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TREATMENT

• Procedures used include FNA, cyst aspiration and parotidectomy.
• Surgery for parotid lesions requires parotidectomy via an incision hidden in skin crease in front of ear. Main risk is facial nerve paralysis.
• Diagnostic and therapeutic procedure for parotid tumors is superficial parotidectomy. Total parotidectomy required with involvement of both superficial and deep lobes.
• Intraop facial nerve monitoring available to improve identification of the nerve during surgery and avoid injury.

• Intralesional doxycycline injection useful for growth prevention (in 75%) and even regression (in 25%) in the setting of benign parotid cysts.

• Can use in setting of severe facial deformity with benign lymphoepithelial cyst, but risk of secondary malignancy.
• Rarely used as sole modality in the treatment of tumors. Adjuvant radiotherapy offered in some situations.

• ABx in setting of sialadenitis, gram positive coverage with amoxicillin/clavulanate 500 mg PO tid (or clindamycin 300 mg PO q6h in PCN-allergic pts) is usually sufficient. May require parenteral ABx if severe.
• HAART and oral prednisone in presence of DILS.

• Option in setting of cyst if pt is asymptomatic and no significant cosmetic deformities.

• Aids in Dx.
• Help resolve aesthetic concerns. May be repeated.

Drug Comments

FOLLOW UP

• Typically only as needed if undergoing aspiration for lymphoepithelial cyst.
• Post-surgical follow-up for malignancy more frequent to survey for recurrence, particularly in setting of high-grade lesions.
• Some salivary gland tumors can occur bilaterally.

OTHER INFORMATION

• Other treatment for sialadenitis includes rehydration, warm compresses, sialogogues, parotid massage and oral irrigations. If no improvement after 2-3 days consider CT or U/S to evaluate for abscess.
• FNA for Dx of solid lesions and monitoring in pts with DILS for development of EBV-associated NHL. FNA sensitivity and specificity of 91% and 98%, respectively.
• CT and MRI useful in setting of neoplasm. Can correlate size/location of lesion. Ultrasound most useful in setting of benign lymphoepithelial cyst. Advantages include simplicity, inexpensive, painless, noninvasive and no radiation exposure.
• Lab work to consider includes mumps titer, CBC, autoimmune and Sjogrens profile (ss-A, ss-B, ANA, ESR)
• Timely referral to otolaryngologist if uncertain Dx, suspicion of malignancy, or for surgical management.

REFERENCES