[Metastasizing pleomorphic adenoma of the submandibular gland: a case report].

Metastasizing pleomorphic adenomas without histological evidence of malignancy have rarely been reported. A case of 30-year-old woman with a mass which showed a benign pleomorphic adenoma appearanced histologically in the left submandibular gland and right supercollarbone respectively was described. Eight years ago, the patient suffered from pleomorphic adenoma of the left submandibular gland. It revealed histopathologic features consistent with the recurrent and metastasizing tumor. The clinic pathological features, possible mechanism and prevention approach of metastasizing pleomorphic adenoma were discussed based on previously reports in the literature.