Carcinosarcoma of the parotid gland: Report of a case with parapharyngeal presentation

Abstract

The parapharyngeal or lateral pharyngeal space extends from the skull base to the hyoid bone and can give rise to a wide variety of benign and malignant neoplasms. ~ Even though varied tumors of this area are rare and comprise only 0.5% of head and neck neoplasms, 2 80% are benign whereas 20% are malignant. 3 The most common primary neoplasm of the parapharyngeal space is derived from salivary gland tissue, either the deep lobe of the parotid gland, or minor salivary gland tissue in the area. 1 Only 2% of all parotid tumors present as parapharyngeal space tumors. 4 Pleomorphic adenomas represent the majority of these parapharyngeal parotid tumors. 1 Carcinosarcoma, or true malignant mixed tumor (TMMT), is rare tumor of the salivary gland. It is included in the broad group of malignant tumors associated with pleomorphic adenoma. Other tumors comprising this category are carcinoma ex pleomorphic adenoma (the most common in this group) and metastasizing mixed tumor. 5 Carcinosarcoma is thought to arise possibly from a pleomorphic adenoma and consists of both carcinomatous and sarcomatous elements. 5 If metastatic disease occurs, both components usually metastasize together. 5 It is among the rarest of malignant tumors of the salivary glands, occur-