Metastasizing Pleomorphic Adenoma of the Parapharyngeal Space to the Cervical Lymph Node: A Case Report

Background: Pleomorphic adenoma (PA) is the most common benign salivary gland tumor. Despite its benign histological appearance, rare cases demonstrate metastatic potential without malignant transformation, termed metastasizing pleomorphic adenoma (MPA). Case Presentation: Here in we report a case of a 32-year-old female with no comorbidities, presenting with a left parapharyngeal mass. MRI revealed a well-circumscribed, lobulated lesion inseparable from the deep lobe of the parotid, with heterogeneous enhancement and cystic/necrotic components. Histo pathological examination of the resected mass revealed pleomorphic adenoma. Interestingly, metastatic deposits with identical histology were identified within the excised cervical lymph node. Conclusion: This case highlights the paradoxical behavior of pleomorphic adenoma, which, although histologically benign, may metastasize. Awareness of MPA is crucial for clinicians to ensure long-term surveillance following the excision of pleomorphic adenomas.