Carcinosarcoma ex pleomorphic adenoma of the parotid gland: a case report

Carcinosarcoma ex pleomorphic adenoma is an extremely rare malignant neoplasm of the salivary gland that originates from a pre-existing benign tumor. Malignant transformation of the pleomorphic adenoma is extremely rare. The management of carcinosarcoma ex pleomorphic adenoma remains challenging because of its rarity, behavioral aggressiveness and resemblance to benign pleomorphic adenoma. Herein, we present the case of a 75-year-old male resident of Saudi Arabia with a history of a swelling in the right parotid gland for more than 25 years, which grew slowly with time. He underwent surgical removal with superficial parotidectomy. Afterward, histological examination of the resected tumor revealed features of carcinosarcoma, and he was diagnosed with carcinosarcoma ex pleomorphic adenoma. He presented again with recurrence of the tumor, which was managed with total parotidectomy and a combination of radiotherapy and chemotherapy. At 12-month follow-up, the patient showed no evidence of disease recurrence or distant metastasis.