Salivary gland neoplasm

Salivary gland cancer
Classification and external resources
The major salivary glands: the Parotid gland (1), where most salivary gland tumors form, the Submandibular gland (2), and the Sublingual gland (3).
ICD-10	C07-C08, D11
ICD-9	142, 210.2
MedlinePlus	001040
MeSH	D012468

Salivary gland cancer is a cancer that forms in tissues of a salivary gland. The salivary glands are classified as major and minor. The major salivary glands consist of the parotid, submandibular, and sublingual glands. The minor glands include small mucus-secreting glands located throughout the palate, nasal and oral cavity.^[1] Salivary gland cancer is rare, with 2% of head and neck tumors forming in the salivary glands, the majority in the parotid.^[2]

Classification

Benign tumor of the submandibular gland, also known as pleomorphic adenoma, presented as a painless neck mass in a 40-year-old man. At the left of the image is the white tumor with its characteristic cartilaginous cut surface. To the right is the normally lobated submandibular salivary gland.

Salivary gland neoplasms are classified by the World Health Organization as primary or secondary, benign or malignant, and by tissue of origin.^[3] This system defines five broad categories of salivary gland neoplasms:^[4]

• malignant epithelial tumors (e.g. acinic cell carcinoma, mucoepidermoid carcinoma and adenoid cystic carcinoma, salivary duct carcinoma)
• benign epithelial tumors (e.g. pleomorphic adenoma, myoepithelioma and Warthin tumour, sebaceous lymphadenoma)
• soft tissue tumors (Hemangioma)
• hematolymphoid tumors (e.g. Hodgkin lymphoma)
• secondary tumors.

Signs and symptoms

Signs include fluid draining from the ear, pain, numbness, weakness, trouble swallowing, and a lump. The most common symptom of major salivary gland cancer is a painless lump in the affected gland, sometimes accompanied by paralysis of the facial nerve.

Causes

The chief risk factor is chewing tobacco, followed by smoking. Other risk factors include older age, radiation therapy treatment to head or neck, and being exposed to certain carcinogenic substances at work.

Pathogenesis

Diagnosis

In most cases, local excision with a margin of normal tissue is the appropriate form of biopsy for a major salivary gland tumor. In the parotid region, this requires identification of the facial nerve. For submandibular tumors, the entire submandibular triangle is cleared. In contrast, minor salivary gland tumors have a higher likelihood of being malignant, and an incisional biopsy is performed initially so that definitive treatment can be planned. In the parotid region, the presence of pain, recent rapid enlargement of a preexisting nodule, skin involvement, or facial nerve paralysis suggests cancer. Enlarged cervical lymph nodes in association with a salivary gland tumor are considered a manifestation of cancer until proved otherwise. Fine-needle aspiration is indicated if accurate diagnosis will allow for better treatment planning.

Prevention

Treatment

Treatment may include the following:

• Surgery with or without radiation.
• Radiation therapy.
• Chemotherapy.

Surgery

Radiotherapy

Fast neutron therapy has been used successfully to treat salivary gland tumors,^[5] and has shown to be significantly more effective than photons in studies treating unresectable salivary gland tumors.^[6][7]

Chemotherapy

Prognosis

Epidemiology

History

See also

• Head and neck cancer

Notes

References

External links

• Salivary gland cancer entry in the public domain NCI Dictionary of Cancer Terms
• The Patients Forum on Tumors Of The Parotid Gland
• Clinically reviewed salivary gland cancer for patients from Cancer Research UK.

 This article incorporates public domain material from the U.S. National Cancer Institute document "Dictionary of Cancer Terms".