Pleomorphic Adenoma
By Ruth Pierre
Oral Pathology 2018
Section: Thursday PM
Overview
The Pleomorphic Adenoma is a lesion in which its name follows its characteristics. The term “pleomorphic” is used to describe this lesions ability to alter its shape or size in response to environmental conditions. Most importantly, however, the term “pleomorphic” is used because this neoplasm has a dual origin from epithelial and myoepithelial elements. An Adenoma is a tumor formed in a gland made up of epithelial tissue. The pleomorphic adenoma is a benign tumor. However, this salivary gland disorder does have a malignant potentiality. Like many tumors, the chances of a Pleomorphic Adenoma becoming cancerous increases with time. According to this study by the University of Pittsburg, the chance of malignancy is less than 5% when the adenoma is found within a few years. Thus, early detection is important. (1) (2)
The Pleomorphic Adenoma is the most common Salivary gland tumor and occurs predominantly in the Parotid Salivary gland. According to the Ethiopian Journal of Health Sciences, 85% of Pleomorphic Adenomas occur in the Parotid Salivary gland, 10% occur in the minor salivary glands, and 5% occur in the submandibular glands. (1)
As aforementioned, this condition has a potential for malignancy, and this tumor occurs frequently in the Salivary glands. Thus, it is important for oral health care professionals to be knowledgeable on this topic. Updated facts and statistics about Pleomorphic Adenomas will be discussed below.
Etiology
The etiology of the Pleomorphic Adenoma is currently unknown. However, there are risk factors which increase the risk of developing this tumor. For example, people who are older in age are at a higher risk for developing this condition. The pleomorphic adenoma is most common in the third to sixth decades of life. Another risk factor for the pleomorphic adenoma is excess exposure to radiation.
Clinical Presentation
The Pleomorphic Adenoma presents is a slow growing swelling of the tissue. This swelling will present wherever the salivary gland associated is located. The patient may experience a lump in the jaw, neck or mouth. The patient may report difficulty swallowing, difficulty chewing, and/or hoarseness.
The clinician will observe facial asymmetry and a well-defined swelling of one side that increases in size over time. Upon palpation, the clinical will feel a single, firm, mobile, well circumscribed mass. (3)
Demographic
Pleomorphic adenomas may occur in any age. However, it is most common between the third and sixth decades of life. This condition is more common in females than males with a 2:1 ratio. (4)
Biopsy / Histology / Radiographs
To diagnose a Pleomorphic Adenoma, a biopsy and knowledge of its histology is required. A fine needle aspiration is most commonly used to diagnose this condition. An MRI, CT scan or an Ultrasound may also be used as an adjunct to confirm findings.
Histologically, the pleomorphic adenoma will consist of epithelial and myoepithelial cells with different growth patterns. (3)
Radiographically, the image will show a lobular mass with circumscribed borders. The Pleomorphic adenoma will have a higher signal intensity than the lymph nodes. This helps the clinician differentiate between the lymph nodes and pathology.
Differential Diagnosis
The pleomorphic adenoma may exhibit symptoms related to TMJ disorders. For example, a patient with Pleomorphic adenoma may experience trouble chewing and pain close to the TMJ.
Treatment
The treatment for a Pleomorphic Adenoma is surgical excision. The most common operation is a superficial parotidectomy. During this surgery, the surgeon would remove the outer part of the parotid gland down to the level of the facial nerve branches. Another option is a total parotidectomy. In this surgery, the superficial gland is separated from the facial nerve branches. Then, the deep portion of the gland is removed. Treatment is encouraged due to this salivary gland disorders risk of becoming malignant. (3)
Prognosis
The prognosis of a pleomorphic adenoma is excellent after excision. Therefore, treatment is encouraged. Pleomorphic Adenoma has a recurrence rate of 8-45%. This is reduced to 5% with a superficial parotidectomy and 0.4% with a total parotidectomy. It could take up to 50 years for this to recur. If left untreated, pleomorphic adenoma has a potential for malignancy. (6)
Professional Relevance/ Enhancement of Clinical Understanding
A dental hygienist is an important member on the oral healthcare team. Thus, it is important for dental hygienists to have updated information on oral diseases and their treatments. In addition, the dental hygienist plays an important role in the discovery of these conditions on patients. For example, dental hygienists are responsible for administering intra-oral and extra-oral exams. Knowledge of the disorders and diseases of the mouth will help a hygienist to understand what the structures that are being palpated feel in sickness and in health.
The role of a hygienist does not stop there. As aforementioned, the treatment of a Pleomorphic Adenoma is surgical excision of the gland affected. In response, the patient is likely to have a decrease in the production of saliva. Thus, patients are likely to experience xerostomia, discomfort, develop caries, and more. Hygienists are experienced in treating and educating patients on topics like these. Therefore, the hygienist has a role in this treatment process.
Citations*
- S Jain, S. (2018). Pleomorphic Adenoma of the Parotid Gland: Report of a Case With Review of Literature. [online] PubMed Central (PMC). Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4478272/#!po=2.00000[Accessed 19 Nov. 2018].
- Dentistry3000.pitt.edu. (2018). [online] Available at: https://dentistry3000.pitt.edu/ojs/index.php/dentistry3000/article/download/70/64[Accessed 28 Nov. 2018].
- Emedicine.medscape.com. (2018). Pathology of Pleomorphic Adenoma: Definition, Epidemiology, Etiology. [online] Available at: https://emedicine.medscape.com/article/1630933-overview#a5[Accessed 3 Nov. 2018].
- Bokhari, M. and Greene, J. (2018). Adenoma, Pleomorphic. [online] Ncbi.nlm.nih.gov. Available at: https://www.ncbi.nlm.nih.gov/books/NBK430829/#!po=10.0000[Accessed 3 Nov. 2018].
- Stathopoulos, P., Igoumenakis, D. and Smith, W. (2018). Partial Superficial, Superficial, and Total Parotidectomy in the Management of Benign Parotid Gland Tumors: A 10-Year Prospective Study of 205 Patients.
- Jin Soo, L. (2016). Recurrent Pleomorphic Adenoma of the Parotid Gland. [online] Pubmed. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5556878/[Accessed 18 Nov. 2018].
*Works are cited in the order of which they appear.