Pleomorphic adenomas, also known as benign mixed tumors, are a type of tumor that can affect any of your major or minor salivary glands. Here are five things you need to know about pleomorphic adenomas.

What are the symptoms?

If you develop a pleomorphic adenoma, you will notice a swollen area near the affected salivary gland. This swollen area tends to be fairly soft and painless, and the swelling grows slowly. These tumors are easy for patients to miss and tend to be discovered by dentists during routine examinations.

Most of these tumors affect the parotid glands. The parotid glands are major salivary glands that are located on the side of your face, just in front of your ears. The next most common location is in the submandibular glands. These glands are in between your Adam's apple and your chin. If you notice swelling in these areas, see your dentist for an evaluation.

What causes pleomorphic adenomas?

The precise cause of pleomorphic adenomas still isn't known, but there are a few possible causes. Some studies have found that these tumors tend to occur 15 to 20 years after a person is exposed to radiation, so they may be caused by radiation exposure. Other studies have linked the tumor to simian virus 40. This is a virus carried by monkeys, and some polio vaccines given before 1963 were contaminated with it. 

Are they cancerous?

These tumors are benign, which means that they're not cancerous. However, this doesn't mean that they're harmless and don't require treatment. One possible complication is that if the tumor gets large enough, it can press against the nerves in your face and cause numbness or tingling.

How are pleomorphic adenomas treated?

Your dentist will refer you to an oral surgeon to have your tumor surgically removed. The entire tumor as well as a margin of healthy tissue will be removed. After your surgery, you will be monitored to make sure that the tumor doesn't recur. 

Are they common?

Pleomorphic adenomas are fairly common. The annual incidence of these tumors is between 2 and 3.5 cases per 100,000 people. Studies have reported that these tumors make up between 45% and 75% of all salivary gland tumors, which makes them the most common type of tumor in this area. Anyone can develop this tumor, but it is twice as common among females as among males, and the average age at diagnosis is between 43 and 46.

If you notice a swelling on your face or inside your mouth, see a dentist, like those represented at http://www.nwidentist.com/ right away.