Pleomorphic adenoma

Seminar on Pleomorphic Adenoma

1. SALIVARY GLAND TUMOR Dr: Ahmed A.Shoeeb

2. Pleomorphic Adenoma Description. the most common tumor of the salivary glands overall , it accounts for about 60% of all salivary gland tumors. It is often called a mixed tumor because it consists of both epithelial and mesenchymal elements. The majority of these tumors are found in the parotid glands , with less than 10% in the submandibular, sublingual, and minor salivary glands Pleomorphic adenomas may occur at any age, but the highest incidence is in the fourth to sixth decades of life . It also represents the most common salivary neoplasm in children .

3. Clinical Presentation . These tumors appear as painless , firm , and mobile masses that rarely ulcerate the overlying skin or mucosa In the parotid gland these neoplasms are slow growing and usually occur in the posterior inferior aspect of the superficial lobe In the submandibular glands they present as well-defined palpable masses It is difficult to distinguish these tumors from malignant neoplasms and indurated lymph nodes Intraorally

4. pleomorphic adenomas most often occur on the palate , followed by the upper lip and buccal mucosa . Pleomorphic adenomas can vary in size, depending on the gland in which they are located. In the parotid gland, the tumors are usually several centimeters in diameter but can reach much larger sizes if left untreated . When observed in situ, the tumors are encased in a pseudocapsule and exhibit a lobulated appearance

5. Pathology. The gross appearance of pleomorphic adenoma is that of a firm smooth mass within a pseudocapsule. Histologically , the lesion demonstrates both epithelial and mesenchymal elements. The epithelial cells make up a trabecular pattern that is contained within a stroma. The stroma may be chondroid , myxoid , osteoid , or fibroid . The presence of these different elements accounts for the name pleomorphic tumor or mixed One characteristic of a pleomorphic adenoma is the presence of microscopic projections of tumor outside of the capsule .

6. Treatment. 1-SURGICAL REMOVAL WITH ADEQUATE MARGINS IS THE PRINCIPAL TREATMENT. Because of its microscopic projections 2-this tumor requires a wide resection to avoid recurrence 3-In spite of the capsule, close excision should not be attempted 4-A superficial parotidectomy is sufficient for the majority of these lesions . A small tumor in the tail of the parotid gland may be removed with a wide margin of normal tissue sparing the remainder of the superficial lobe 5-lesions that occur in the submandibular gland are treated by the removal of the entire gland.

7. Choice of imaging modality for pleomorphic adenoma Computed tomography (CT) is one of the primary imaging modalities used to assess tumors of the salivary glands. It allows the detection of lesions and assessment of their extension and characteristics as well as their relationships to nearby structures However, this technique has some limitations, and higher accuracy levels might be obtained through magnetic resonance imaging (MRI).

8. Pleomorphic adenoma of the left parotid gland with a round, painless, rubber-like swelling over the left ramus region below the ear, covering the lower border of the mandible near the angle

9. Axial computed tomography scan (encircled area enlarged) showing, (a) well-defined, hypodense, heterogeneous mass in the left parotid gland (white arrow) with poorly defined anteromedial margin (black arrow); (b) variable areas of low attenuation seen on the posterior aspect of the superficial lobe (white arrow)

10. CT image shows a lobular mass in the left parotid gland. The circumscribed borders and location are highly suggestive of pleomorphic adenoma, which was confirmed with fine-needle aspiration.

11. Axial magnetic resonance imaging showing, (a) a well-defined hypointense mass with low signal intensity foci in the lower pole of the left parotid gland (white arrow) on T1 image (b) a heterogeneously hyperintense mass with a star-like low signal foci in the center (white arrow) and a hyperintense foci in the lower pole of the left parotid gland (black arrow) on T2 images

12. Axial contrast-enhanced CT scan demonstrates a poorly enhancing mass (pleomorphic adenoma) involving the left submandibular gland. The mass is smoothly marginated and causes the gland to expand

13. THANK YOU AHMED MOHAMED A.Shoeeb