Pleomorphic Adenoma

Pleomorphic adenomas are rare benign (noncancerous) tumors that can develop on your salivary glands. While these tumors are benign, they can turn into cancerous tumors. For that reason, healthcare providers typically recommend surgery to remove them. Once removed, pleomorphic tumors rarely come back.


A pleomorphic adenoma (at right) is a benign (noncancerous) tumor that may develop on your salivary glands.
Pleomorphic adenomas are benign (noncancerous) tumors that may develop on your salivary glands. They may look like small lumps inside of your mouth (as shown) in front of your ears or under your jaw.

What is a pleomorphic adenoma?

A pleomorphic adenoma is a benign (noncancerous) tumor that can affect your salivary glands, particularly your parotid glands. Surgeons treat these tumors by removing all or part of the affected gland. Once removed, pleomorphic adenomas typically don’t come back.

How common are pleomorphic adenomas?

Pleomorphic adenomas are rare. They affect an estimated 3 per 100,000 people in the U.S. However, they’re the most common type of benign salivary gland tumor. Anyone may develop this tumor, but they typically affect women and people assigned female at birth (AFAB) between ages 30 and 70.


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Symptoms and Causes

What are the symptoms of a pleomorphic adenoma?

Pleomorphic adenoma symptoms may appear:

  • In the area in front of your ear (pleomorphic adenoma of parotid gland).
  • Under your jaw (pleomorphic adenoma of submandibular gland).
  • On your hard or soft palate (small salivary glands).

These tumors grow very slowly, so you may not have symptoms right away. Symptoms include:

  • A single painless lump under the skin near your jaw, by your ear or in your mouth.
  • The lump may feel soft or firm.
  • Typically, the lump will move when you push on it with your fingers.

Most pleomorphic adenomas measure 2 centimeters (about the size of a peanut) to 6 centimeters (about the size of an egg). Without treatment, however, pleomorphic adenomas may grow to be quite large, measuring as much as 35 centimeters (approximately 13 inches).

What causes pleomorphic adenomas?

Medical researchers don’t know exactly what causes pleomorphic adenomas. They have identified a few potential risk factors:

  • Exposure to radiation. Some studies suggest people may develop pleomorphic adenomas 15 to 20 years after having radiation therapy for head and neck cancer.
  • Exposure to certain chemicals used to manufacture rubber, asbestos mining or in plumbing.

What are the complications of pleomorphic adenomas?

Around 5% of pleomorphic adenomas turn into cancerous tumors known as carcinoma ex pleomorphic adenomas. Medical researchers don’t know why this happens.

Diagnosis and Tests

How are pleomorphic adenomas diagnosed?

Healthcare providers diagnose pleomorphic adenomas by doing a physical examination and asking about your symptoms. They may order the following tests:


Management and Treatment

How are pleomorphic adenomas treated?

The most common treatment is surgery to remove all or part of the gland affected by a pleomorphic adenoma. For example, a surgeon would treat a pleomorphic adenoma of parotid gland by performing a parotidectomy.

What are possible surgery complications?

All surgery comes with potential complications, including:

  • Reaction to anesthesia.
  • Excessive bleeding.
  • Infection.
  • Facial nerve damage leading to temporary or permanent facial paralysis.
  • Frey syndrome: Facial nerves that are cut during surgery sometimes grow back to connect with your sweat glands. When this happens, you may sweat when you chew.
  • Trouble speaking or swallowing: Damage to nerves in your face and mouth may make it hard for you to speak or swallow.
  • Scarring: Surgery to remove salivary gland tumors may leave scars that you can see.


Can pleomorphic adenomas be prevented?

Medical researchers aren’t sure what causes a pleomorphic adenoma, so there’s no way to prevent one.

Outlook / Prognosis

What’s the outlook for pleomorphic adenomas?

More than 90% of pleomorphic adenomas removed with surgery don’t come back. That means surgery cures the condition.

Living With

How do I take care of myself?

The best way to take care of yourself is to keep an eye on new lumps near your jaw or ear. If they don’t go away within a week or so, contact a healthcare provider. You may wonder if it makes sense to contact a healthcare provider about a new lump or bump that doesn’t go away. The short answer is yes, it does make sense. And you’d be in good company. Unusual lumps and bumps are among the most common reasons why people see providers.

While it’s not likely, new lumps near your jaw or ear may be a symptom of pleomorphic adenomas on your parotid or submaximal glands. Pleomorphic adenomas aren’t cancer, but they can turn into cancerous tumors.

When should I go to the emergency room?

If you needed surgery to remove a pleomorphic adenoma, ask your surgeon about any complications from surgery that may require immediate medical care.

What questions should I ask my healthcare provider?

You may want to ask the following questions:

  • Do I have more than one of these benign tumors?
  • What are my treatment options?
  • Will treatment cure the tumor?

A note from Cleveland Clinic

Pleomorphic adenomas are benign (noncancerous) tumors that may develop on your salivary glands. They may look like small lumps in front of your ears, under your jaw or inside of your mouth. These tumors grow very slowly, so you can have a pleomorphic adenoma for years before noticing symptoms. Rarely, some tumors become cancerous. Fortunately, surgery to remove the tumors cures the condition.

Medically Reviewed

Last reviewed by a Cleveland Clinic medical professional on 06/12/2023.

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