Salivary Gland Tumors

• • Paired major salivary glands include parotid, submandibular, and sublingual glands

  • Minor salivary glands are distributed in the mucosa of the lips, cheeks, hard and soft palate, uvula, floor of mouth, tongue, and peritonsillar region

  • Few salivary glands in the nasopharynx, paranasal sinuses, larynx, trachea, bronchi, and lacrimal glands

Epidemiology

• • About 5% of head and neck tumors are in the salivary glands

  • 5 times more prevalent in major than minor salivary glands (70% in parotids)

  • Malignancy rates by gland:

  • -15% of parotid tumors

    -50% of submandibular tumors

    -90% of minor salivary gland tumors

  • 70% of parotid tumors are pleomorphic adenomas (50% of all salivary gland tumors)

  • Mixed tumors are more common in women, with peak incidence in fifth decade

  • Warthin tumor accounts for 5% of parotid tumors

  • -Typically occur in men in sixth and seventh decade of life

    -10% bilateral

  • Monomorphic tumors are rare and seen most commonly in the minor salivary glands of the lip

  • Mucoepidermoid carcinoma is the most common parotid cancer

  • Acinic cell carcinomas are found almost exclusively in the parotid

  • Descending frequency of minor salivary gland carcinomas: Adenoid cystic, adenocarcinoma, mucoepidermoid

  • 70% of minor salivary gland carcinomas occur in the oral cavity, principally hard palate

Symptoms and Signs

• • Nodule in the parapharyngeal space

  • Enlarged cervical lymph nodes

  • Pain

  • Weakness in the muscles of facial expression

  • Trismus

  • Cranial nerve palsies

Imaging Findings

• • CT or MRI: Can identify extent of salivary gland mass, extension in surrounding nerves, and local nodal spread

• • Majority of tumors derived from intercalated and excretory duct cells; rarely, myoepithelial cells

  • Benign neoplasms of the salivary gland:

  • -Pleomorphic adenoma

    -Mixed tumor

    -Monomorphic adenomas

    -Oncocytoma

    -Warthin tumor (papillary cystadenoma lymphomatosum)

  • Malignant neoplasm of the salivary gland:

  • -Acinic cell carcinoma

    -Adenocarcinoma

    -Adenoidcystic carcinoma

    -Malignant mixed tumor

    -Mucoepidermoid carcinoma

    -Squamous cell carcinoma

    -Undifferentiated carcinoma

  • In parotid region, presence of pain, rapid enlargement of preexisting nodule, skin involvement or facial nerve paralysis suggests cancer

  • Enlarged cervical lymph nodes in association with salivary gland tumors are considered manifestations of cancer until proven otherwise

Rule Out

• • For swelling in the parotid gland:

  • -Parotitis

    -Primary parotid tumor

    -Upper jugular chain lymph node enlargement

    -Tumor of the tail of the submandibular gland

    -An enlarged preauricular or parotid lymph node

    -A branchial cleft cyst

    -An epithelial inclusion cyst

    -Mesenchymal tumor

• • Complete history and physical exam

  • Biopsy

  • -Either fine-needle aspiration or local excisional biopsy with margin of normal tissue

  • For minor salivary gland, often perform incisional biopsy to plan for definitive treatment (as these are more often malignant)

Surgery

• • Benign tumors are removed with margin of normal tissue

  • For low-grade salivary gland cancers, ...