Parotid Gland Tumor

A parotid gland tumor is an abnormal growth of cells in one of your parotid glands, which are the largest salivary glands located in front of and below your ears. Most of these tumors are non-cancerous (benign), but some can be cancerous (malignant). Early detection and treatment are important for the best outcomes.

What is Parotid Gland Tumor?

A parotid gland tumor is an abnormal growth that forms in the parotid glands, which are the largest of your salivary glands. These glands are located on each side of your face, just in front of your ears. Most parotid gland tumors are non-cancerous (benign), meaning they do not spread to other parts of the body, but some can be cancerous (malignant).

Your parotid glands produce saliva, which helps with digestion and keeps your mouth moist. When cells in these glands grow abnormally, they can form a lump or mass, which is a tumor. These tumors can vary greatly in size and type. While the majority of parotid gland tumors are benign, it is important to have any new lump or swelling checked by a doctor. Benign tumors, such as pleomorphic adenomas or Warthin's tumors, typically grow slowly and do not spread. Malignant tumors, like mucoepidermoid carcinoma or adenoid cystic carcinoma, can grow more quickly and have the potential to spread to nearby tissues or distant parts of the body. Understanding whether a tumor is benign or malignant is crucial for determining the correct treatment plan. Even benign tumors may need to be removed because they can sometimes grow very large, cause symptoms, or, in rare cases, change into a cancerous tumor over time.

Symptoms

The most common symptom of a parotid gland tumor is a painless lump or swelling in front of or below your ear, or in your jaw or neck area. While many tumors are benign and cause no other symptoms, cancerous tumors may also cause pain, numbness, or weakness on one side of your face.

You might first notice a parotid gland tumor as a soft or firm mass that you can feel under your skin. This lump usually grows slowly over time. Because the parotid gland is close to the facial nerve, which controls facial movements, a tumor can sometimes affect this nerve. If the tumor is cancerous or growing aggressively, it might press on the facial nerve, leading to symptoms such as numbness in part of your face or muscle weakness on one side of your face. This weakness can make it difficult to smile, close your eye, or move your mouth. Other signs that could suggest a more serious tumor include persistent pain in the area of the salivary gland, difficulty swallowing, or trouble opening your mouth widely. It is important to remember that these symptoms do not always mean you have a cancerous tumor. Many benign conditions can cause similar signs. However, any new or changing lump, especially if accompanied by pain or facial weakness, should be evaluated by a healthcare professional.

Causes & risk factors

The exact cause of most parotid gland tumors is not fully understood. However, certain factors can increase your risk of developing one. These include exposure to radiation, older age, and, in some cases, certain workplace exposures or viral infections.

While the specific triggers for parotid gland tumors are often unknown, research has identified several factors that may increase a person's risk. One significant risk factor is previous radiation exposure to the head and neck area, such as from radiation therapy for other cancers. This exposure can damage cells and lead to abnormal growth over time. Older age is also a general risk factor for many types of cancers, including some parotid gland tumors. Certain workplace exposures, such as to wood dust or asbestos, have been linked to an increased risk of salivary gland cancers, though this link is less common. Some viral infections, like Epstein-Barr virus (EBV) or human immunodeficiency virus (HIV), have also been associated with an increased risk of certain types of salivary gland tumors. It is important to note that having one or more risk factors does not mean you will definitely develop a parotid gland tumor. Many people with these risk factors never develop a tumor, and many people who develop a tumor have no known risk factors. If you are concerned about your risk, discuss it with your doctor.

How it's diagnosed

Diagnosing a parotid gland tumor typically begins with a physical exam and a review of your symptoms. Doctors then use imaging tests, such as MRI or CT scans, to visualize the tumor. A definitive diagnosis, especially to determine if the tumor is cancerous, usually requires a biopsy.

During a physical exam, your doctor will carefully feel your neck, jaw, and the area around your ears to check for any lumps or swelling. They will also ask about your symptoms, including when you first noticed the lump and if you have experienced any pain or facial weakness. This initial assessment helps guide further diagnostic steps. Imaging tests are crucial for understanding the tumor's size, location, and relationship to surrounding structures, like the facial nerve. A magnetic resonance imaging (MRI) scan uses strong magnets and radio waves to create detailed images of soft tissues. A computed tomography (CT) scan uses X-rays to produce cross-sectional images. Sometimes, an ultrasound may also be used to get a clearer view of the lump. The most important diagnostic step is often a biopsy, which involves taking a small sample of tissue from the tumor for examination under a microscope. A common type is a fine-needle aspiration (FNA) biopsy, where a thin needle is inserted into the lump to collect cells. This procedure helps determine if the tumor is benign or malignant and identifies the specific type of tumor, which is essential for planning treatment.

Treatment options

The primary treatment for most parotid gland tumors, whether benign or malignant, is surgery to remove the tumor. For cancerous tumors, surgery may be followed by additional treatments like radiation therapy. Chemotherapy is rarely used for parotid gland cancers.

Surgery, known as a parotidectomy, is the most common and often the most effective treatment. The goal of surgery is to remove the entire tumor while preserving the facial nerve, which runs through the parotid gland. The extent of surgery depends on the tumor's size, location, and whether it is benign or malignant. For smaller, benign tumors, only a part of the gland may be removed (superficial parotidectomy). For larger or cancerous tumors, more of the gland may need to be removed (total parotidectomy). If the tumor is cancerous, your doctor may recommend radiation therapy after surgery. Radiation therapy uses high-energy beams to kill any remaining cancer cells and reduce the risk of the cancer returning. This is often used if the tumor was large, aggressive, or if there's a concern that not all cancer cells could be removed during surgery. Chemotherapy, which uses drugs to kill cancer cells throughout the body, is rarely a primary treatment for parotid gland cancers. It may be considered in very specific situations, such as when the cancer has spread to distant parts of the body or if other treatments have not been effective. Your treatment plan will be tailored to your specific tumor type, stage, and overall health, and will be discussed in detail with your healthcare team.

Recovery & outlook

The recovery and outlook for a parotid gland tumor depend significantly on whether the tumor is benign or cancerous, its size, and if it has spread. Most benign tumors have an excellent outlook after surgical removal. Cancerous tumors require more aggressive treatment, and their outlook varies based on the cancer's stage and type.

For benign parotid gland tumors, the outlook after successful surgical removal is generally very good, with a low chance of recurrence. However, even after surgery for benign tumors, some people may experience complications. One common concern is temporary or, less commonly, permanent facial nerve damage, which can lead to weakness or paralysis on one side of the face. This occurs because the facial nerve runs through the parotid gland and can be stretched or injured during surgery. Another potential complication is Frey's syndrome, where you might sweat or flush on your cheek while eating. This happens when nerves that control saliva production mistakenly grow into sweat glands in the skin. Numbness in the earlobe or jaw area is also common due to nerve disruption during the procedure. Your surgeon will discuss these potential risks with you before the operation. For malignant parotid gland tumors, the outlook is more variable. It depends on factors like the type of cancer, how advanced it is (its stage), and whether it has spread. Early detection and complete surgical removal, often combined with radiation therapy, offer the best chance for a good outcome. Regular follow-up appointments are essential after treatment for both benign and malignant tumors to monitor for any recurrence or new symptoms.

When to see a doctor

You should see a doctor if you notice any new or persistent lump or swelling in your jaw, neck, or in front of or below your ear. It is especially important to seek medical attention if you experience pain, numbness, or weakness on one side of your face, or have difficulty swallowing or opening your mouth.

Any new lump or swelling, even if it is painless, warrants a visit to your doctor. While many parotid gland tumors are benign, only a medical professional can properly evaluate the lump and determine its nature. Early diagnosis is key for effective treatment, especially if the tumor turns out to be cancerous. Pay close attention to any changes in the lump, such as rapid growth or the development of pain. Red-flag symptoms that require prompt medical evaluation include any signs of facial nerve involvement, such as a drooping eyelid, an inability to smile fully, or numbness in your cheek or lip on one side. These symptoms could indicate that a tumor is growing quickly or is cancerous. Do not delay seeking medical advice if you experience trouble swallowing, persistent hoarseness, or difficulty opening your mouth widely. These could be signs that a tumor is affecting nearby structures. Your doctor can perform an examination and recommend appropriate diagnostic tests to determine the cause of your symptoms and guide you toward the right care.

Frequently asked questions

Are all parotid gland tumors cancerous?

No, most parotid gland tumors are non-cancerous (benign). However, some can be cancerous (malignant). It is essential to have any new lump or swelling evaluated by a doctor to determine its nature.

What is the main treatment for a parotid gland tumor?

The main treatment for most parotid gland tumors, whether benign or malignant, is surgery. This procedure, called a parotidectomy, aims to remove the tumor while preserving the facial nerve.

Can a parotid gland tumor affect my face?

Yes, a parotid gland tumor can affect your face, especially if it grows near or presses on the facial nerve. This can lead to symptoms like numbness, muscle weakness, or paralysis on one side of your face.

What is Frey's syndrome?

Frey's syndrome is a potential complication of parotid gland surgery where you might experience sweating or flushing on your cheek while eating. It occurs when nerves that control saliva production mistakenly grow into sweat glands in the skin.

How is a parotid gland tumor diagnosed?

Diagnosis typically involves a physical exam, imaging tests like MRI or CT scans, and a biopsy. A fine-needle aspiration (FNA) biopsy, which collects tissue for microscopic examination, is often used to determine if the tumor is benign or malignant.

Will I need radiation or chemotherapy for a parotid gland tumor?

For cancerous parotid gland tumors, radiation therapy may be recommended after surgery to kill any remaining cancer cells. Chemotherapy is rarely used for these cancers, typically only in specific advanced cases.

Sources

• MedlinePlus — Parotid Gland Tumor
• Mayo Clinic — Parotid Gland Tumor
• Cochrane Library — Parotid Gland Tumor