Carcinoma Ex Pleomorphic Adenoma: Is It a High-Grade Malignancy?

PURPOSE: The objective of this study was to investigate the clinicopathologic features of carcinoma ex pleomorphic adenoma (CXPA) and comprehensively improve an understanding of this disease. MATERIALS AND METHODS: This retrospective study investigated 151 cases of histologically confirmed CXPA. Disease-specific survival, local recurrence, and regional and distant metastases were analyzed. RESULTS: Most cases were classed as frankly invasive CXPA (135 of 151). More than half these cases (73 of 135; 54.1%) developed local recurrence; 25 (18.5%) developed cervical metastasis; 21 (15.6%) developed distant metastasis; and 60 patients (55.6%) died during follow-up. In contrast, only 1 patient in the noninvasive CXPA group (n = 10) died after treatment for lung metastasis and 1 patient developed cervical metastasis. Similarly, only 1 patient in the minimally invasive CXPA group (n = 6) died of lung metastasis and the remaining 5 patients had an uneventful recovery after treatment. CONCLUSIONS: Frankly invasive CXPA was a high-grade malignancy with an unfavorable prognosis. Elective neck dissection should be performed in cases of frankly invasive CXPA that originate in the submandibular gland. Patients with minimally invasive and noninvasive CXPA should be followed closely after primary treatment because regional or distant metastasis can occur.