# Clinicopathologic Features and Postoperative Outcomes of Parotidectomy: A 16-Year Retrospective Cohort Study from a Tertiary Referral Center

## TL;DR

This study analyzed 314 parotidectomy cases over 16 years to understand tumor types and outcomes, focusing on facial nerve function and risk factors for complications.

## Contribution

The study introduces a risk-stratified follow-up approach based on histopathologic features to improve postoperative care for parotidectomy patients.

## Key findings

- Malignant tumors were linked to higher surgical margin positivity, capsular invasion, and tumor necrosis compared to benign tumors.
- Facial nerve paralysis was more common in malignant cases and after extensive lymph node dissection.
- Benign tumors like pleomorphic adenoma occasionally showed aggressive features such as capsular invasion and necrosis.

## Abstract

Background: Parotid gland tumors pose diagnostic and surgical challenges due to their histological heterogeneity and proximity to the facial nerve. This study aimed to evaluate clinicopathological features and postoperative outcomes with a specific focus on facial nerve function in patients undergoing parotidectomy. Methods: This retrospective study included 314 patients who underwent parotidectomy between 2008 and 2024 at a tertiary center. Demographic data, tumor histology, and postoperative complications—particularly facial nerve paralysis within the first three months—were analyzed. Histopathological features including capsular, perineural, and lymphovascular invasion were also assessed. Results: Of all cases, 79% were benign, 14.6% malignant, and 6.4% non-neoplastic. Pleomorphic adenoma and Warthin tumor were the most common benign entities, while mucoepidermoid carcinoma was the most frequent malignancy. Malignant tumors were associated with higher rates of positive surgical margins (44.2% vs. 12.5%, p < 0.001), capsular invasion (25% vs. 7%, p < 0.001), and tumor necrosis (22% vs. <1%, p < 0.001). Facial paralysis occurred in 4.4% of patients, largely transient and significantly associated with malignant tumors (p < 0.001) and extensive lymph node dissection (p < 0.001). Capsular invasion and necrosis were rare in benign lesions but still observed, especially in pleomorphic adenoma. Conclusions: Histopathologic aggressiveness markers were associated with malignant disease and postoperative facial nerve dysfunction. These findings support a risk-stratified approach to follow-up: all patients undergo universal early assessment at two weeks and three months, after which surveillance intensity may be individualized according to histopathologic features—such as necrosis, perineural invasion, capsular invasion, or positive margins.