What do the salivary glands do?

The salivary glands are located around the mouth. They produce saliva, which moistens food to aid chewing and swallowing.

Saliva contains enzymes that begin the digestion process, and help cleanse the mouth by washing away bacteria and food particles. By keeping the mouth moist, saliva helps to keep dentures, retainers, or other orthodontic appliances in place.

There are three pairs of major salivary glands. The largest are the parotid glands, located in each cheek over the jaw in front of the ears. Two submandibular glands are at the back of the mouth on both sides of the jaw. There are many sublingual glands  under the floor of the mouth.

All of the salivary glands empty saliva into the mouth through ducts that open at various locations in the mouth.

What are salivary gland tumours?

Salivary gland tumours arise from abnormal growth of  cells that sit in the salivary glands or line the ducts that drain saliva into the mouth..

What causes salivary gland tumours?

 Swelling of the salivary glands is most commonly due to:

  • Abdominal surgery
  • Cirrhosis of the liver
  • Infections
  • Other cancers
  • Salivary duct stones
  • Salivary gland infections
  • Sarcoidosis
  • Sjogren’s syndrome

Salivary tumours are rare and the most common type of salivary  tumour is a pleomorphic adenoma of the parotid gland. This is usually a non-cancerous growth that gradually increases the size of the gland. However, some salivary   tumours can be cancerous (malignant).

Malignant salivary gland tumours are usually carcinomas.

What are the symptoms of salivary gland tumours?

A painless swelling in one of the salivary glands (in front of the ears, under the chin, or the floor of the mouth); the size of the swelling gradually increases causing difficulty moving one side of the face- this is known as facial nerve palsy.

Obtain a referral to see Professor Sidhu if:

  • You have pain when eating or chewing
  • You notice a lump in the mouth, under the jaw, or in the neck that does not go away in 2 – 3 weeks or is getting larger

Exams and Tests

An examination by a health care provider or dentist shows a larger than normal salivary gland, usually in one of the parotid glands.

Tests may include:
X-rays of the salivary gland (called a sialogram) to look for a stone or obstruction to a salivary duct
CT scan or MRI to verify that there is a mass in a salivary gland and to see if cancer has spread to lymph nodes in the neck
Salivary gland biopsy or fine needle aspiration to determine if the tumour is noncancerous (benign) or cancerous (malignant)

Treatment

The recommended treatment is usually a salivary gland tumour surgery to remove the affected salivary gland. If the tumour is noncancerous (benign), no other treatment is usually needed. Surgery on the parotid gland usually helps maintain the function of the nerve that controls the muscles of the face.

Radiation therapy or extensive surgery may be required if the tumour is cancerous.

Possible Complications

Tumours in the parotid gland require an incision in front of the ear and into the side of the neck to expose the gland and the facial nerve.This nerve provides power to muscles of the side of the face. The nerve has 5 branches and is at risk of damage during parotidectomy. Professor Sidhu has performed hundreds of these operations and uses a neuromonitor to minimise damage to branches of the facial nerve.His current permanent injury rate is less than 2% for non cancerous parotid tumours.

Following parotid surgery it is common to have a small amount of saliva accumulate under the incision in the first few weeks.This will stop with time.

Rarely, surgery to remove a parotid cancer can injure the facial nerve, which controls movement of the face.Sometimes,  the nerve has to be sacrificed for cancer clearance. Nerve reconstructon is possible to maintain tone in the facial muscles.

References

Scianna JM, Petruzzelli GJ. Contemporary management of tumours of the salivary glands. Curr Oncol Rep. 2007;9:134-138.