Unusual Metastases from a Pleomorphic Adenoma of the Parotid Gland: A Case and Literature’s Review

Background: Pleomorphic adenoma constitutes the most common benign parotid gland tumor. Local recurrence after surgery has been described in 1% 5% of cases, and malignant evolution in 2% 9% of cases. Metastasizing pleomorphic adenomas has rarely been reported. No histologic or molecular parameters exist at the present time that could predict the development of metastasis in these neoplasms. Methods and Results: A 54-year-old woman had a superficial left parotidectomy with facial nerve preservation for pleomorphic adenoma. She developed two recurrences in 2000 and 2001, but 25 years later the first operation she presented a metastasis in her right gluteal region with evidence of local recurrence. Conclusion: Metastatizing pleomorphic adenoma is a rare pathologic situation but, in case of swelling or lump appearance in patients with pleomorphic adenoma history, it should be taken in mind.