What happens next: unexpected malignancies after extracapsular dissection of parotid tumors.

BACKGROUND: Extracapsular dissection (ECD) is commonly used for benign parotid tumors because of its low morbidity. Unexpected malignant diagnoses after ECD raise concerns regarding oncologic adequacy and postoperative management. AIMS/OBJECTIVES: To evaluate the long-term oncologic and functional outcomes of patients with unexpected malignant parotid tumors treated with ECD. MATERIAL AND METHODS: A retrospective review was performed of patients who underwent ECD for presumed benign parotid tumors between 2012 and 2020. Patients with a final malignant histopathological diagnosis and a minimum follow-up of 60 months were included. Demographic, pathological, treatment, and outcome data were analyzed. RESULTS: Seventeen patients met the inclusion criteria. Histopathological diagnoses included low-grade mucoepidermoid carcinoma (52.9%), adenoid cystic carcinoma (17.7%), acinic cell carcinoma (17.7%), intermediate-grade mucoepidermoid carcinoma (5.9%), and secretory carcinoma (5.9%). Three patients (17.6%) underwent completion superficial parotidectomy because of positive margins; no residual tumor was identified. Two patients received adjuvant radiotherapy. Mean follow-up was 89.7 months (range, 61-138 months). No local recurrence was observed, and all surviving patients remained disease-free. No transient or permanent facial nerve dysfunction or other procedure-related complications occurred. CONCLUSIONS AND SIGNIFICANCE: ECD provided excellent long-term oncologic and functional outcomes in carefully selected patients with unexpected low-grade parotid malignancies when negative surgical margins were achieved. Additional treatment may be required for positive margins or higher-risk pathological features.