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

Pleomorphic adenoma (PA), originally called mixed tumour, is the most common neoplasm of the salivary glands. It is usually a benign, slow-growing and well-circumscribed tumour. However, PA may occasionally give rise to metastases that usually occur after a previous recurrence. These tumours display benign histological features in both primary tumours and metastases. Such tumours have been termed metastatic PA or metastatic mixed tumours. We report a case of metastatic PA of the submandibular gland with metastasis to the cervical lymph nodes.