The Uncommon Location of Pleomorphic Adenoma: A Clinical Case Report.

relato de caso clínico

Abstract

Introduction: Pleomorphic adenomas are benign neoplasms that affect the salivary glands and exhibit significant histological diversity.¹ According to the World Health Organization (WHO), pleomorphic adenoma is defined as a localized tumor with pleomorphic or mixed characteristics of epithelial origin, intertwined with myxoid, mucoid, and chondroid tissue masses.²,³ Clinically, pleomorphic adenoma usually presents as a slow-growing, painless, and firm swelling.⁴ Additionally, it does not typically cause ulcerations in the underlying mucosa. A systematic review conducted in 2020, including 22 full articles, reported that the age of onset of pleomorphic adenoma ranged from 13 to 75 years, with an average of 44.14 years. Females were more affected, with a ratio of 13 women to 8 men. Regarding the location, the most commonly affected areas by the tumor were the neck, followed by the hard palate, upper lip, soft palate, nasopharynx, submandibular region, external auditory canal, and earlobe.²

Case Description: A 42-year-old male patient of black ethnicity presented to the Stomatology Clinic of the Federal University of Vales do Jequitinhonha and Mucuri with a complaint of a "lump" at the "corner" of the mouth. According to the patient's information, an acne-like lesion appeared in the labial commissure area, and after local trauma, it gradually and painlessly increased in size. On extraoral clinical examination, a nodule was observed near the labial commissure, with normal sensitivity and color, a fibroelastic consistency, a smooth surface, and an ovoid shape. The lesion had raised edges, a sessile insertion, and a regular contour, measuring approximately 2 x 1.5 x 0.3 cm. No abnormality was found on the overlying skin. Additionally, no intraoral correlation with the extraoral nodule was identified. Based on the clinical findings, the diagnostic hypotheses included epidermoid/dermoid cyst, fibrous hyperplasia, neurofibroma, fibrolipoma, and pleomorphic adenoma. An excisional biopsy of the lesion was performed under local anesthesia. Intradermal suturing was done, and the specimen was sent for histopathological analysis. The postoperative period was uneventful.

Results: Microscopic examination revealed fragments of a well-defined benign neoplasm originating in the minor salivary glands, delimited by a fibrous capsule. The neoplastic epithelial cells proliferated to form nests, cords, and duct-like structures, with eosinophilic material inside. Myoepithelial cells proliferated and formed chondroid stromatization, which predominated throughout the lesion. The histopathological diagnosis was pleomorphic adenoma. After 7 days, the patient returned, and excellent recovery was observed. As it was an aesthetic area, the choice of intradermal suturing was found to be beneficial, resulting in satisfactory healing.

Final Considerations: There are few reports in the literature regarding pleomorphic adenoma in locations outside the commonly affected regions. Therefore, it is crucial for the dental surgeon to have knowledge of their field, recognize the need for a comprehensive and thorough clinical examination, for early detection of pathologies and establishment of appropriate treatment. Furthermore, it is important to discuss this topic in an academic setting in light of the scientific literature.