High-Grade Mucoepidermoid Carcinoma Ex Metastasizing Pleomorphic Adenomas in the Parotid Gland and Parapharyngeal Space: a Case Report and Literature Review

ABSTRACT

Pleomorphic adenoma is the most common benign neoplasm of the salivary glands. Its three malignant variants include carcinoma ex pleomorphic adenoma, carcinosarcoma, and metastasizing pleomorphic adenoma. Among the subtypes of carcinoma ex pleomorphic adenoma, high-grade mucoepidermoid carcinoma has rarely been reported. Additionally, metastasizing pleomorphic adenoma is rare.We report the imaging findings of a high-grade mucoepidermoid carcinoma ex metastasizing pleomorphic adenoma of the parotid gland and parapharyngeal space in a 42-year-old man.