A salivary gland tumor is an abnormal growth of cells that occurs in the salivary gland or surrounding ducts. While some salivary gland tumors are malignant, the most common tumors are benign. Salivary gland tumors are typically firm, painless growths; however, they can grow to such an extent that they affect nearby nerves resulting in facial paralysis or palsy.
Common Benign Salivary Gland Tumors
Between 70 and 80 percent of salivary gland tumors are classified as pleomorphic adenomas. These non-cancerous growths most often occur in the parotid gland; however, they can also affect the submandibular and lingual glands as well as other minor glands.
Slow-growing tumors known as Warthin’s tumors are painless and are most often seen in smokers and older adults. These growths are the second most common type of non-cancerous salivary tumor. Warthin’s tumors tend to occur bilaterally in the parotid glands.
Common Malignant Salivary Tumors
The most common malignancies affecting the salivary glands are mucoepidermoid carcinomas. These tumors occur when cells multiply and grow uncontrollably. Mucoepidermoid tumors are normally painless and present as a fixed, firm mass.
Acinic cell carcinomas most often develop in the parotid gland. Although slow-growing, these tumors can be locally aggressive. Unlike mucoepidermoid tumors, acinic cell carcinomas may be tender and painful. These tumors tend to develop in patients at a slightly younger age than other types of salivary tumors. The majority of patients with acinic cell carcinomas are diagnosed in their early 50s.
Adenoid cystic carcinomas are a much less common form of salivary tumor. More than one-quarter of cancers affecting the submandibular salivary gland are adenoid cystic carcinomas. Initially, these tumors may be painless, but they can cause facial paralysis and pain as they progress. It is possible for these tumors to spread to the nerves and even the lungs.
Squamous cell carcinomas account for approximately 90 percent of cancers affecting the head and neck. Most early-stage squamous cell carcinomas can be treated using an in-office surgical procedure. Once the cancer advances, more aggressive surgery or even radiation may be required.
A benign pleomorphic adenoma can become a malignant tumor known as a carcinoma ex-pleomorphic. The risk of the benign tumor becoming malignant increases the longer the tumor goes untreated. Indications that a tumor may have become malignant include:
- Rapid growth
- Facial weakness or numbness
How Salivary Gland Tumors are Diagnosed
An otolaryngologist may use a variety of diagnostic tests to confirm the presence of a salivary gland tumor and to determine if the growth is malignant, including a complete medical history and physical exam, endoscopy, and imaging tests. If a tumor is identified, the doctor may perform a biopsy to determine if the growth is malignant.
Treatment for Salivary Gland Tumors
Approximately 20 percent of parotid tumors, 50 percent of submandibular tumors, and 65 percent of sublingual and minor salivary gland tumors are cancerous. Treatment typically involves surgery to remove the affected gland as well as radiation, chemotherapy, or both. A patient’s long-term prognosis depends on the type, location, and stage of the cancer as well as their age and general health.