Metastasizing Pleomorphic Adenoma

Pleomorphic adenoma (PA) is the most common salivary gland neoplasm. On a molecular level PA is characterized by a translocation involving PLAG1 or HMGA2. PA is considered to be a benign tumor although it can undergo malignant transformation. Alternatively, cases of histologically benign PA "metastasizing" to lymph nodes or distant body sites are well documented. Several theories have been proposed to explain this behavior. However, there is a...