A Case Report of Pleomorphic Adenoma of the Lower Lip: An Uncommon Location and a Diagnostic Pitfall

Pleomorphic adenoma is the most common benign tumor of the salivary glands. Lower lip involvement is uncommon, and its nonspecific clinical appearance may complicate the diagnosis. We report a case of a man in his 30s who presented with a painless lower lip swelling that had gradually increased in size over several months. The lesion had initially been considered a sebaceous cyst and had been treated unsuccessfully with a topical corticosteroid. Clinical examination revealed an approximately 1-cm, firm, mobile, well-defined submucosal nodule covered by normal-appearing mucosa. Given the lesion's persistence and uncertainty regarding the clinical diagnosis, it was excised under local anesthesia and submitted for histopathological examination, which confirmed a pleomorphic adenoma with epithelial and myoepithelial components within a chondromyxoid stromal background. The postoperative course was uneventful, with no clinical evidence of recurrence during the six-month follow-up period; however, continued long-term clinical surveillance was planned. This case highlights the importance of including minor salivary gland tumors in the differential diagnosis of persistent lower lip swellings, even when they appear clinically benign, and underscores the key role of histopathological examination in establishing the diagnosis.