Giant pleomorphic adenoma of the parotid gland with malignant transformation.

A 72-year-old female is described who was admitted to the hospital with a giant mixed tumor of the left parotid gland that had grown to a weight of 6051 g within 20 years and ultimately underwent resection of the mass. Histopathological examination revealed adenocarcinoma cells with hyperchromatic nuclei and mitotic figures proliferated in pleomorphic adenoma. Many authors have reported giant tumors weighing more than a few kilograms of the parotid glands, and most were benign. The present tumor was the sixth largest among all the parotid tumors, including both benign and malignant, which were reported. Furthermore, our case was the largest one confirmed as malignant recorded in the world literature. The tumor was successfully resected with no marked facial nerve paralysis.