General Information / Anatomy / Function / Statistics

• There are 3 major salivary glands, they produce saliva which keeps the mouth and throat moist between meals and helps with swallowing and digestion of food. Saliva also supplies the minerals needed to maintain healthy teeth.
• The parotid glands are pyramid shaped, the base is the superficial lobe which is horseshoe shaped and lies around the ear, the apex is the deep lobe which lies between the jaw bone (mandible) and the inside of the throat. The parotid glands are the most common site for malignant tumours.
• The facial nerve, which controls the movements of the muscles of the face, passes between the superficial and deep lobes. It may be damaged by parotid cancer or sometimes during a difficult parotid operation. This results in weakness of the facial muscles:
  • The submandibular (or submaxillary) glands lie just below the angle of the jaw bones
  • The sublingual glands lie under the mid portion of the tongue
  • The minor salivary glands are scattered throughout the lining of the mouth, throat, trachea and esophagus. They provide lubrication

Symptoms / Signs

• Painless lump or swelling
• Facial weakness or paralysis

Etiology / Carcinogens / Risks

• The cause is unknown
• Some benign tumours can grow aggressively and there are some rare cases where these benign tumours have caused death by recurring and invading the tissues of the face or brain

Diagnosis / Staging / Grading / Types

• Physical examination
• Needle aspirate (biopsy) of lump
• CT scan where indicated

Types

Benign tumours

• Pleomorphic adenoma, also called mixed parotid tumour. Not malignant but tends to recur if not completely removed.
• Small proportion may become malignant if left untreated
• Warthins tumour, often doesn't need treatment usually doesn't recur after adequate excision

Malignant tumours

• 95% are adenocarcinomas
• Different types vary in their capacity to recur after surgery or the likelihood that they will spread either to the lymph nodes in the neck or via the bloodstream

Treatment

• Surgery is the treatment of choice for both benign or malignant tumours
• Operation will involve removal of the primary tumour +/- removal of the lymph glands on the same side of the neck if the tumour is malignant
• Post-operation radiation therapy is indicated if the risk of recurrence is high
• Radiation therapy alone may be given for unresectable tumours
• Tumours of the salivary glands (either the parotid, the submandibular, sublingual or the minor salivary glands) are usually treated by surgery, sometimes followed by radiotherapy
• Radical neck dissection is needed when the tumour has spread to lymph nodes
• Chemotherapy is sometimes used in special circumstances when radiation or surgery are refused, or for recurrent or unresponsive tumours

Prognosis

• Very good for benign tumours
• Wide range for malignant tumours although most are relatively slow growing

Revised April 1998