Occasional Diagnosis of Metastatic Pleomorphic Adenoma

Background: Pleomorphic adenoma is considered a biologically benign tumour. However, rare cases of metastases, showing the same histological benign features of the primary tumour, are reported, thus justifying the inclusion into the World Health Organization (WHO) definition “Malignant Mixed Tumour”, even in the absence of histological atypias. Case report: We report the case of a 45years-old woman affected by recurrent pleomorphic adenoma since about the age of 30years. During pre-surgical x-ray chest, performed as routine before excision of the last recurrence of pleomorphic adenoma, bilateral lung nodules were discovered, which ended up to be lung metastases. Discussion: it had been proved by evidence that pleomorphic adenoma recurrences significantly increase the possibility both of malignant transformation of the disease and malignant behaviour recurrences that could develop distant localization, though histologically benign. Conclusion: in management of primary pleomorphic adenoma radical surgical excision is crucial, to prevent first of all local recurrences and then distant spread.