What is the Parotid Gland?
The parotid gland is one of the major salivary gland whose function is to produce saliva. There are two parotid glands present that are located on each side of the face, in front of the ears and stretch towards the lower borders of the jawbones. The parotid glands are responsible for secreting thin saliva that travels into the mouth to help with chewing and digesting of food.
What are Parotid Gland Tumors?
Abnormal growths occurring inside the parotid gland are known as parotid gland tumors. Majority of these growths are benign in nature, i.e. they are non-cancerous; however, in some cases, they can be malignant (cancerous) also. Rarely, the growths seen on the parotid gland can be enlarged lymph nodes or tumors originating from other location, which have metastasized into the parotid glands. Around 80% of tumors which originate from the parotid tissue are benign and slow growing; whereas, malignant parotid tumors have a variety of types and characteristics where some of them can be fast growing and fatal.
Causes of Parotid Gland Tumors
The exact cause of parotid gland tumor is not clear. It is thought that the tumor develops as a result of mutations in DNA of the parotid cells, which allow rapid division and multiplication of the cells leading to accumulation of cells and resulting in formation of tumor.
Symptoms of Parotid Gland Tumors
- Presence of swelling or a lump near the jaw or in the mouth or neck.
- Weakness of the facial muscles on one side.
- Facial numbness.
- Patient can experience difficulty in swallowing.
- There may be persistent pain in the region of parotid gland.
- Patient has difficulty in opening his/her mouth widely.
Diagnosis of Parotid Gland Tumors
An ENT (Ear, Nose, and Throat) doctor will help in confirming the diagnosis of parotid gland tumor. A careful medical history and complete physical examination of the patient is done. Imaging tests, such as CT scan or MRI scan helps in determining the position and size of the parotid tissues. Fine needle biopsy can be done of the parotid tissues to look for presence of malignant cells.
Treatment of Parotid Gland Tumors
Surgery is the main treatment of choice for parotid gland tumors where the parotid gland can be removed either partially or completely (parotidectomy). Parotidectomy can also be done for chronic infection of the parotid gland and if there is an obstruction of the flow of the saliva from the parotid gland leading to chronic enlargement of the parotid gland.
If the parotid gland tumor is benign, is not increasing in size and the patient is not having any symptoms, then observation of the condition can be done. This is particularly recommended if the patient's general health is not good and it is unsafe for the patient to undergo general anesthesia. However, surgery is always advised because the benign parotid tumors can potentially turn cancerous, which can be more difficult to remove if they remain like that for a longer time and continue to increase in size.
Risks of Parotidectomy
Scar: Patient will have a scar in front of the ear traveling down to the upper part of the neck. In most of the patients, the healing of the scar goes well and some patients may have a slightly raised and red colored scar that fades gradually. Rarely, patient can develop a keloid or a thick scar. Other than this, there is a slight hollow seen in the jaw area or cheek from where the parotid tissue was removed.
Facial Weakness: The facial nerve which is responsible for controlling facial movements travels through the parotid gland. Facial nerve is also important for closing the eyes, moving the lips and wrinkling the nose. In majority of the cases, the parotid gland can be removed without any facial nerve damage. However, if the parotid gland tumor is large in size or if its position is such that the surgeon has to remove the facial nerve, or its small branches in order to ensure complete removal of the tumor, then this could result in permanent facial paralysis. Other than this, if the facial nerve is not permanently injured, then also there may be facial weakness present or decreased motion of the facial muscles, as the nerve recovers from the parotidectomy.
Numbness: There can be numbness felt in the outer edge of the ear and the earlobe after parotidectomy, which usually resolves gradually.
Salivary Fistula: In rare cases, saliva secreted from the remaining parotid tissue can drain through an opening in the skin incision. Treatment is done with compressive dressings and healing is achieved in a few days.
Frey's Syndrome: After parotidectomy, about a minority of the patients may experience sweating on the side of the face where surgery was done during eating. In many cases, this is minor and not noticeable. However, if it becomes bothersome, then medications can be prescribed for relief.
Other Complications: These include infection, bleeding and general anesthesia complications which are the risks associated with every surgery, but rarely occur with parotid surgery.