Salivary gland tumors
Salivary gland tumors present as a painless, slowly enlarging gland mass; 85% arise in the parotid, where 75% to 80% are benign (most often pleomorphic adenoma, then Warthin tumor), whereas submandibular, sublingual, and minor gland tumors are more often malignant (mucoepidermoid and adenoid cystic carcinoma). Pain, facial nerve weakness, fixation, or cervical nodes signal malignancy; imaging followed by fine-needle aspiration or core needle biopsy establishes the diagnosis, and surgical excision with facial nerve preservation is the treatment for benign and malignant tumors alike.
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What this article covers
- Overview
Neoplasms of the major (parotid, submandibular, sublingual) or minor salivary glands: they present as a chronic, unifocal, painless, slowly growing mass and may be benign or malignant.
- Epidemiology
Pleomorphic adenoma: the most common salivary gland tumor in adults, slightly more common in women, arising mostly in the parotid gland and next in the submandibular gland.
- Risk factors
Prior head and neck radiation: ionizing radiation increases the risk of pleomorphic adenoma and mucoepidermoid carcinoma.
- Pathophysiology
Pleomorphic adenoma is a benign mixed tumor: epithelial and myoepithelial cells, ductules, and a chondromyxoid stroma form a heterogeneous, slow-growing mass.
- Clinical features
Hallmark: a chronic, unifocal, painless, slowly enlarging firm mass in the preauricular or parotid region (or submandibular triangle) that does not change with eating, distinguishing it from obstructive salivary disease.
- Differential diagnosis
Metastatic squamous cell carcinoma to a neck node: a new neck mass in a smoker older than 40 years is malignant until biopsy proves otherwise; look for a mucosal primary; see head and neck squamous cell carcinoma.
- Diagnosis
The diagnosis is established by tissue: cytology from fine-needle aspiration (FNA) or histology from ultrasound-guided core needle biopsy confirms the tumor type (for example, mixed epithelial and…
- Management
First, obtain tissue and refer every salivary gland mass for surgical excision, the mainstay of treatment whether the tumor is benign or malignant.
- Complications
Facial nerve paralysis: from tumor invasion (mucoepidermoid and adenoid cystic carcinoma) or as a surgical injury; the most consequential complication.
- Prognosis
Benign tumor outcome depends on complete resection: recurrence of pleomorphic adenoma is driven by residual pseudopods after incomplete excision.
- Prevention
Evaluate any persistent salivary or neck mass promptly: a new neck mass in a smoker older than 40 years is treated as malignant until biopsy proves otherwise, and any oral lesion persisting more than 2 to 3 weeks needs evaluation and biopsy.
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