Surgical Management for Benign Parotid Tumors: Review of a 16-year Experience with 633 Patients

Abstract

The objective of this study was to analyze the diagnosis and postoperative complications of benign parotid tumors for a series of 633 patients who underwent the same diagnostic methods and operation procedure in a single institute. A series of 633 patients who underwent parotidectomy for benign parotid tumors over a 16-year period was reviewed. There were 345 female and 288 male patients. The site of the tumors was divided among three groups, superficial, deep, and lower pole tumors. The numbers of each type of above tumors were 342, 122, and 169 cases, respectively. The most common pathology of the parotid tumor was a pleomorphic adenoma (372 cases) followed by a Warthin tumor (166 cases). Pleomorphic adenomas and Warthin tumors accounted for 85% of all benign tumors. The accuracy rate of fine needle aspiration cytology (FNAC) for all benign tumors was 71%, 84% for pleomorphic adenomas and 72% for Warthin tumors. Transient facial nerve dysfunction was observed in 130 patients (21%) in 612 cases of primary benign parotid tumors, and only one patient developed a permanent weakness. The incidence of transient facial nerve dysfunction was 18% in superficial tumors, 39% in deep tumors, and 15% in lower pole tumors. Significant risk factors for development of a transient facial palsy were the site of the tumors, the size of the tumors, operation time, and bleeding volume. Among these risk factors, for the site of the tumors, the deep lobe was the most important factor associated with transient facial nerve dysfunction. Transient facial nerve dysfunction recovered within 6 months in 90% of all cases. The accuracy rate of FNAC for benign parotid tumors was 72%. The incidence of transient facial nerve dysfunction in deep tumors was significantly higher compared to that in superficial and lower pole tumors. According to the rate of facial palsy, operation time, and bleeding volume, benign parotid tumor should be divided among three groups, namely superficial, deep, and lower pole tumors.