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

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.

To evaluate the long-term oncologic and functional outcomes of patients with unexpected malignant parotid tumors treated with ECD.

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.

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.

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.