Carcinoma ex pleomorphic adenoma: Diagnostic dilemma and treatment protocol

Carcinoma ex pleomorphic adenoma (CXPA) is a carcinoma arising from a primary or recurrent benign pleomorphic adenoma. It often poses a diagnostic challenge to clinicians and pathologists. The entity is difficult to diagnose preoperatively. Pathological assessment is the gold standard for making the diagnosis. Treatment for CXPA often involves an ablative surgical procedure, which may be followed by radiotherapy. We report a case of a 65-year-old lady with a history of recurrent swelling in the left preauricular region and a history of surgery 10 years back, in the same region. Preoperatively, a diagnosis of pleomorphic adenoma of the parotid gland metastasizing to the cervical lymph node was made, but postoperatively it was reported as CXPA adenoma of the parotid gland. A radical parotidectomy involving en bloc resection of the facial nerve along with deep and superficial lobes of the parotid was performed followed by radiotherapy. The fact that pleomorphic adenomas are classified as benign tumors should not overshadow the wide range of biological behaviors associated with these tumors. On account of the potential for malignant transformation, surgical treatment must be properly performed. Surgery followed by radiotherapy should be considered as the standard care for a patient with carcinoma ex pleomorphic adenoma.