A Case of Parotid Carcinoma Ex Pleomorphic Adenoma with Mixture of Malignant Subtypes

Abstract

Carcinoma ex pleomorphic adenoma is an uncommon malignant salivary gland tumor that arises from a longstanding pleomorphic adenoma. The carcinomatous component of carcinoma ex pleomorphic adenoma can possess virtually any histologic subtype of salivary gland cancer. We experienced a case of a 61-year-old patient who presented with a right parotid mass that was initially palpated 20 years ago, with a sudden increase in size in the last few months. Radiological and cytological findings from fine needle aspiration biopsy could not exclude malignancy. Total parotidectomy and selective neck dissection were performed for treatment, and carcinoma ex pleomorphic adenoma with mixed carcinoma components of salivary duct carcinoma and myoepithelial carcinoma was diagnosed. After receiving postoperative radiation of 6000 cGy over 6 weeks, there has been no recurrence up to the 18-month follow-up. We report this rare case of carcinoma ex pleomorphic adenoma with mixed malignancy subtypes, accompanied by a review of literature.