Three Cases of Noninvasive Carcinoma ex Pleomorphic Adenoma of the Parotid Gland and a Literature Survey Focusing on their Clinicopathologic Features

Abstract

Only 30 cases of non-invasive carcinoma ex pleomorphic adenoma have been reported in the English language literature. Here, we report on three cases of non-invasive carcinoma ex pleomorphic adenoma. Only one of the 33 patients showed recurrence or metastasis after surgery most likely as a result of benign pleomorphic adenoma. Pleomorphic adenoma with focal areas showing malignant changes should be carefully assessed by serial sectioning. The prognosis and therapeutic appoach will depend on evidence of capsular invasion. HER-2/neu is a useful marker in the differential diagnosis of pleomorphic adenoma versus noninvasive carcinoma ex pleomorphic adenoma.