1. Abstract ID: Assigned exhibit number:OC_104 Title: Pleomorphic adenoma of the cheek in a young female: a case report
Maryam Shahrzad,MD,1 Menachem Gold, MD 1,Rawle Philbert ,DDS,FACD 2 1.Department of Radiology, Lincoln Medical Center, Bronx, NY, Department of Dentistry/Oral and Maxillofacial Surgery, Lincoln Medical Center, Bronx, NY,

2. Conflict of Interest
None Declared

3. Purpose
The minor salivary glands are considered small independent mucous glands scattered in different areas of the upper respiratory tract. Although the majority of minor salivary glands are found in the palate,the submucosa of the uvula, inner surface of the lips, parotid duct opening, mucus membrane of the cheek, floor of the mouth, palatoglossal folds, superior pole of the tonsil, and inferior surface of the tongue are all potential locations for minor salivary glands. [1]

4. Introduction/Background
Pleomorphic adenoma is the most common benign tumor affecting the salivary glands, mainly arise from the parotid and submandibular glands. It may also affect minor salivary glands in 6.4% of cases [1].This tumor usually presents as a slowly growing, unilateral painless mass, predominantly in females (60%) and during the 3th to 5th decade of life.[1]

5. Introduction/Background
We report the case of a pleomorphic adenoma arising in a minor salivary gland in the buccal mucosa of the cheek in a young female.

6. Case Report
A 26 year old female without any significant past medical history was referred to OMFS clinic from her dental hygienist for evaluation of a left cheek mass present for the past 9 years. The patient denied any pain,ulceration, or discomfort associated with the mass. There was no asymmetry, swelling, lymphadenopathy, or tenderness on extra-oral examination. Cranial nerves 2-12 were grossly intact.

7. Physical Exam
Intra oral examination revealed a well circumscribed 2x2 cm round non-tender lesion which was freely movable. Surface mucosa of the mass resembled surrounding mucosa. Stenson’s ducts were patent bilaterally along with intact dentition and satisfactory oral hygiene.

8. Radiologic Manifestation
Facial bone CT demonstrated a well circumscribed round soft tissue nodule abutting the left mandibular buccal mucosa, measuring 1.6x1.8x2.0 cm. There was no infiltration of the surrounding fat, no associated calcification, and no bone erosion or periosteal reaction.

9. Pathologic Appearance
Patient underwent excisional biopsy of the mass and histologic diagnosis was a mixed tumor (pleomorphic adenoma) of minor salivary gland, which was surrounded by a thin expanse of fibrous connective tissue and scant focally distributed salivary gland tissue, skeletal muscle, and fatty marginal tissue.

10. Follow up
Patient has had no recurrence in four years of follow up.

11. Discussion
Pleomorphic adenoma, which is also known as benign mixed tumor, is comprised of cells with mesenchymal and epithelial differentiation [2]. As the most common benign tumor of salivary gland origin, it most commonly arises in the parotid gland (90%), but it may also occur in minor salivary glands (10%). [1,2]

12. Discussion
With regard to pleomorphic adenomas arising in minor salivary glands, the most common intraoral involvement site is the palate (43-69%), followed by the upper lip (10%), and rarely the cheek mucosa (5.5%). The throat, floor of the mouth, retromolar trigone region and alveolar mucosa are other uncommon sites of occurrence.[2]

13. Discussion
Intraoral pleomorphic adenoma usually presents as a firm, painless, mobile, slowly growing submucosal mass, without ulceration of the overlying mucosa.[1,2]
On CT, pleomorphic adenomas most commonly appear as smoothly marginated or lobulated homogeneous spherical masses. When larger, they can be heterogeneous with foci of necrosis or calcification.

14. Discussion
On MRI, pleomorphic adenomas are characteristically hyperintense on T2-weighted sequences, with a low intensity rim representing the fibrous capsule. They often demonstrate homogeneous enhancement.

15. Discussion
Complete wide excision with a safe margin is usually the treatment of choice for this lesion. Local recurrence is a potential complication as a result of inadequate resection or capsule rupture.[2]

16. Discussion
In case of multiple recurrences, malignant transformation of the tumor should be considered.This happens in 2-7% of the patients. Vascular permeation, perineural invasion, cytologic atypia and an infiltrative growth pattern are pathologic features suggestive of malignancy.[1]

17. References
1.Rao PK, Shetty SR, Hegde D. Ectopic Pleomorphic Adenoma.N Am J Med Sci. 2012;4(4):190-2.
2.Dalati T, Hussein MR.Juvenile pleomorphic adenoma of the cheek: a case report and review of literature.DiagnPathol. 2009;4:32.