Nodal Metastases in Acinic Cell Carcinoma of the Parotid Gland.

The objective of this study was to evaluate the clinical outcome of patients with acinic cell carcinomas of the parotid gland after elective neck dissection (END). A retrospective chart review was performed including 66 patients with acinic cell carcinoma of the parotid gland. Clinical parameters were retrieved and statistically analyzed regarding disease-free survival (DFS) and disease-specific survival (DSS). An END was done in 27 (40.9%) patients, and occult metastases were detected in 4 (14.8%) patients of whom three were low-grade carcinoma. Positive neck nodes were associated with significantly worse DSS (p = 0.05). Intermediate and high-grade carcinoma (HR 8.62; 95% confidence interval (CI): 1.69-44.01; p = 0.010), perineural invasion (HR 19.6; 95%CI: 0.01-0.37; p = 0.003) and lymphovascular invasion (HR 10.2; 95%CI: 0.02-0.59; p = 0.011) were worse prognostic factors for DFS. An END should be considered in patients with acinic cell carcinoma of the parotid gland due to (i) a notable rate of occult neck metastases in low-grade tumors and (ii) the worse DSS of patients with positive neck nodes.