Pleomorphic adenoma of the palatine tonsil: A rare case report and review of the literature

Pleomorphic adenoma is the most common benign neoplasm of the salivary glands, accounting for approximately 60–70% of all salivary gland tumors. Although it most commonly arises within the parotid gland, it may occasionally involve the minor salivary glands of the upper aerodigestive tract. Localization to the palatine tonsil is exceptionally rare, with only a limited number of cases reported in the literature. We report the case of a 48-year-old woman who presented with chronic odynophagia and a sensation of a pharyngeal foreign body evolving over one year. Clinical examination disclosed an asymmetric bilateral tonsillar hypertrophy, predominantly on the right side, without overlying mucosal alteration. Magnetic resonance imaging demonstrated two heterogeneous oropharyngeal masses showing high signal intensity on T2-weighted sequences and heterogeneous enhancement after gadolinium injection, features suggestive of pleomorphic adenoma. The patient underwent bilateral tonsillectomy by cold dissection with bipolar hemostasis under general anesthesia, with uneventful postoperative recovery. Histopathological examination confirmed the diagnosis of pleomorphic adenoma of the tonsil, composed of epithelial and myoepithelial cells embedded in a hyalinized and myxoid stroma, without signs of malignancy. No recurrence was observed on long-term follow-up. Through this case, we review the clinical, radiological, and histopathological features of tonsillar pleomorphic adenoma, and we emphasize the importance of complete surgical excision and sustained long-term surveillance given the risk of local recurrence and late malignant transformation.