A case of pleomorphic adenoma recurred in temporal bone

A rare case of recurrent pleomorphic adenoma of temporal bone in a 67-year-old woman is described. The primary tumor originated in the superficial lobe of the right parotid gland, and was treated with surgery 10 times over 30 years, followed by radiotherapy of 50 Gy. The secondary tumor appeared 32 months after radiotherapy in the right temporal bone, extending to the posterior cranial f ossa and foramen magnum. Right partial temporal bone resection and lateral suboccipital craniotomy were performed on this metastasizing pleomorphic adenoma. Metastasizing pleomorphic adenoma is a very unusual tumor, which appears more likely in cases after incomplete resection. While some of recurred pleomorphic adenoma are pathologically benign, their behavior may become metastatic or clinically malignant in the long run as in the case descrebed here.