What are the causes of pleomorphic adenoma?

Updated July 19, 2017

Pleomorphic adenoma refers to a common tumour found in the salivary glands. Generally it is benign, occurring rarely in children and primarily in women over 40 years old. Most of the time it affects the parotid gland; however, there are rare cases in which it's found in other salivary glands.


The pleomorphic adenoma grows over time at a slow rate, so it's often only diagnosed when the patient notices a mass or during a common examination (dental checkup). There are usually no symptoms other than the growth.


The tumour is made of epithelial and mesenchymal cells. The tumour is not intertwined with the surrounding tissues, so there is a clear delineation.


CAT scans and magnetic resonance imaging are utilised to determine the size of the mass and its location. A biopsy is done to confirm whether the tumour is benign or malignant.


Surgical resection is the most effective way to get rid of the tumour. If complete surgical removal is not possible, in rare cases where the tumour is malignant, radiation therapy is utilised. Total parotidectomy is preferred, if possible, to prevent recurrence.


The most common causes of all salivary gland issues is the inability of the saliva to properly drain, usually from salivary duct blockages. Pleomorphic ademona is generally caused by blockages, but its occurrence has been linked with smoking and exposure to radiation.

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About the Author

Zachary Kaplan has been a freelance writer since 2002, writing articles for "The Link News," as well several health-related websites. He graduated from Colgate University with a Bachelor of Arts in history and minor in literature.