Pleomorphic adenoma of the lip: a case report and literature review

Abstract

Pleomorphic adenoma (PA) most commonly affects the major salivary glands but can also involve the minor salivary glands, particularly those of the hard and soft palate. However, the current study aims to present a case of upper lip PA. A 29-year-old male presented with a painless, firm, slow-growing swelling (1.5 × 1.5 cm) on the left upper lip. Ultrasonography showed a solid, hypoechoic nodule with irregular margins and mild peripheral vascularity. The encapsulated tumor was excised, and histopathology confirmed PA. At the 7-month follow-up, no evidence of recurrence was observed. Though typically seen in adults aged 40-70, PA can affect younger patients. Complete excision with clear margins is essential due to the risk of recurrence or malignant transformation. PA should be considered in the differential diagnosis of upper lip swellings.

Keywords: benign mixed tumor; lip tumor; neoplasm; salivary gland.

Figure 1

(a) Preoperative appearance of the mass located in the upper lip. (b) The excised mass. (c, d) The postoperative appearance of the patient.

Figure 2

(a) The tumor comprised of solid clusters and ductal structures (some of which showed intraluminal papillary formations) lying within a fibrous and chondromyxoid stroma. (b) The ductal structures were lined by a luminal layer of epithelial cells and an abluminal layer of myoepithelial cells. (c) Some areas showed sheets of plasmacytoid myoepithelial cells with bland nuclei. (d) The chondromyxoid stroma contained individual plasmacytoid myoepithelial cells and ductal structures. Hematoxylin and eosin stain; original magnification 40× (a), 400× (b–d).