Pleomorphic adenoma parotid surgery, how much margin we can reach to be safe?

Background: The extent of surgery in cases of parotid gland pleomorphic adenoma (PA) remains challenging. This study aims to evaluate the importance of surgical margins in ensuring safe surgery for patients with PA.

Materials and methods: This prospective study was conducted to evaluate the risk of local recurrence based on surgical margins in patients with parotid PA who underwent superficial or total parotidectomy between May 2019 and November 2021 at a tertiary referral hospital in Tehran, Iran. Patients were followed for at least 2 years. Data were analyzed using SPSS version 23. The normality of data distribution was assessed using the Kolmogorov-Smirnov test. Quantitative and qualitative variables were analyzed with the independent t-test and Chi-square test, respectively. A P < 0.05 was considered statistically significant.

Results: Fifty-seven cases were included in the study. The mean age was 40.7 years, with 37 of 57 (64.9%) patients being female. Of these, 35 of 57 (61.4%) underwent superficial parotidectomy. All tumors were resected with negative margins, with an average safe margin of 0.58 cm (range: 0-3.7 cm). The greatest margin was found at the anterior side (average: 0.76 cm), whereas the smallest margin was at the vertical side (average: 0.39 cm). Postoperative radiotherapy was not administered to patients with close surgical margins. No recurrence was observed after a 2-year follow-up.

Conclusion: In the surgical resection of parotid PA, negative margins are sufficient, and there is no need to obtain additional safe margins to reduce the risk of recurrence. Therefore, extracapsular dissection (which carries higher morbidities) can be replaced by superficial parotidectomy with negative margins (which carries lower morbidities).