Salivary gland tumors are rare and have a global prevalence rate of 0.4–13.5 per 1 lakh persons per year. About 3-6% of all neck and head tumors are salivary gland tumors. Studies indicate a slightly higher rate of prevalence of these tumors in men than in women.
What are salivary gland tumours?
Salivary gland tumors are abnormal cells that grow in the salivary gland or in the ducts tubes that drain the glands.
The tumours may be benign or malignant. Fortunately, more than half of the salivary gland tumours are noncancerous and do not have the potential to spread to other organs. The most common type of salivary gland tumor (80% of all salivary gland tumors) is a slow-growing noncancerious (benign) tumor in the parotid gland.
The purpose of salivary glands is to secrete saliva into the oral cavity. Saliva contains digestive enzymes for facilitating the digestion of food in the mouth. Saliva also contains antibodies that protect the throat and the mouth against infections.
Humans have three major salivary glands in pairs. These are parotid glands, sublingual glands and submandibular glands. Parotid glands are the largest and are the most common site for salivary gland tumours.
Apart from the major salivary glands, there are several minor salivary glands. These are present in the linings of larynx, nose, and mouth. The tumours of the minor salivary glands generally develop in the roof of the mouth.
What are the symptoms of salivary gland tumors?
Several patients with benign tumors do not experience any symptoms. Symptom, if present, may include:
- Facial numbness, usually in a particular part
- Presence of lump or swelling in the mouth or below the jaw
- Facial pain that does not go away
- Difficulty in opening the mouth wide
- Trouble swallowing
- Drainage of fluid from the ear
What causes salivary gland tumors?
The exact cause of salivary gland tumors remains unknown. However, several factors increase the risk of these tumors. Salivary gland tumors occur when there is an alteration in the information stored in the DNA. This alteration results in the abnormal division of cells. Healthy cells die while abnormal cells continue division, which results in the formation of a tumor.
When do you need to see a doctor?
Not all swellings in the salivary glands are tumours. However, do not ignore any of the symptoms of a salivary gland tumor. Early diagnosis and management result in better outcomes. Book an appointment with your doctor if:
- You have a swelling or lump in the jaw, cheek, ear or inside the oral cavity
- You have facial pain and numbness that do not go away
- You have difficulty swallowing food
- You experience weakness in facial muscles
Types of salivary gland tumors
Salivary gland tumors are classified based on the type of cells involved in the tumors.
Types of benign or noncancerous salivary gland tumors include:
- Oncocytoma
- Pleomorphic adenoma
- Warthin tumor
- Basal cell adenoma
- Canalicular adenoma
Types of malignant (cancerous) salivary gland tumors include:
- Squamous cell carcinoma
- Acinic cell carcinoma
- Adenoid cystic carcinoma
- Adenocarcinoma
- Mucoepidermoid carcinoma
- Clear cell carcinoma
- Malignant mixed tumor
- Polymorphous low-grade adenocarcinoma
- Oncocytic carcinoma
- Salivary duct carcinoma
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How are salivary gland tumours prevented?
The occurrence of salivary gland tumours cannot possibly be prevented. However, you may lower the risk by taking the following measures:
- Reduce radiation exposure
- Reduce exposure to chemical substances that may alter the DNA
- Take extra care while working in the asbestos mining and rubber industry
How are salivary gland tumours treated?
The most common treatment option for salivary gland tumors is surgery. Patients with metastatic salivary gland cancer may require chemotherapy or radiotherapy in addition to surgery. The treatment options include:
- Surgery: Surgical intervention depends upon the stage, site and type of tumor. A doctor may remove either a part of or the whole salivary glands.
- Radiation therapy: Radiation therapy may accompany surgery in cases where a surgeon cannot remove cancerous tissues.
- Chemotherapy: The doctor may also prescribe drugs to destroy the salivary gland cancer cells. Doctors generally use this treatment for the management of advanced cancer.
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Conclusion
While most of the salivary gland tumors re benign, it can be malignant, as well. It is important to consult a doctor in case of any symptoms of a salivary gland tumor. Signs of salivary gland tumor include a lump in the jaw, ear and mouth, facial pain and swelling. Early diagnosis and treatment prevent progression and improve prognosis.
Frequently Asked Questions (FAQs)
What risk factors are involved with salivary gland tumors?
Several factors increase the risk of salivary gland tumours. These include old age and exposure to radiation and certain chemicals.
What are the complications from salivary gland tumors?
Undiagnosed or delayed diagnosis of salivary gland tumor, especially malignant tumor, may result in complications. These include cancer progression in the advanced stage resulting in more aggressive therapy, facial disfigurement due to surgery and poor prognosis due to the involvement of multiple organs.
How does a doctor diagnose a salivary gland tumor?
There are various methods of diagnosing salivary gland tumors. These are physical examination, CT scan, MRI, endoscopy, PET scan and biopsy.
