Intraparotid facial nerve schwannoma: a 17-year, single-institution experience of diagnosis and management

Abstract

Background: Intraparotid facial nerve schwannoma (IFNS) is rare and its definite preoperative diagnosis is challenging.

Objective: To improve available knowledge regarding the diagnosis of IFNS and to suggest an appropriate treatment plan.

Material and methods: We retrospectively analyzed medical records of IFNS patients at our hospital. Inclusion criteria were surgery (from January 2000, to December 2016) for a parotid mass, pathologically diagnosed as a schwannoma.

Results: The study included 42 eligible patients who had undergone tumor resection from 5977 parotid tumor patients. Mostly presented hard-textured (18/39) or medium-textured (15/39), with limited mobility (21/39) mass (three tumors were not palpable). Their facial nerve function outcomes were House–Brackmann Grade I (n = 14), Grade II (n = 7), Grade III (n = 11), Grade IV (n = 5), Grade V (n = 3), and Grade VI (n = 2). Significant differences were noted in results based on different surgical methods used (p = .000) and tumor involvement (p = .002).

Conclusions and significance: A hard-textured tumor with limited mobility mass in the parotid gland should prompt the diagnosis of a schwannoma. Tumors involving main trunk usually lead to unsatisfactory facial nerve outcomes. Facial nerve preservation should always be essential, and stripping surgery or intracapsular enucleation could be the preferred surgical methods of choice.

Chinese abstract

背景：腮腺内面神经神经鞘瘤（IFN）罕见, 其明确的术前诊断具有挑战性。

目的：提高对IFN诊断的认识, 并提出合理治疗方案。

材料与方法：回顾性分析我院IFN患者的病历。入选标准为病理诊断为神经鞘瘤的腮腺肿块手术（2000年1月至2016年12月）。

结果：对5977例腮腺肿瘤患者中的42例接受肿瘤切除的患者进行了研究。大多数表现为硬质地（18/39）或中等质地（15/39）, 活动性有限（21/39）肿块（三个肿瘤未被发现）。他们的面部神经功能结果是豪斯-布拉克曼一级（n = 14）、二级（n = 7）、三级（n = 11）、四级（n = 5）、五级（n = 3）和六级（n = 2）。根据不同的手术方法（p=.000）和肿瘤累及程度（p=.002）, 结果有显著差异。

结论和意义：腮腺内移动性有限的硬质地肿瘤应能促使神经鞘瘤的诊断。累及主干的肿瘤通常导致面部神经功能不理想。面神经保护始终应该是必要的, 剥离手术或囊内摘除术应该是首选的手术方法。

Keywords:

• schwannoma
• parotid gland
• facial paralysis
• reconstructive neurosurgery
• nerve sparing surgery

Acknowledgements

We thank Prof. Guangyan Yu, Prof. Xin Peng and Prof. Lei Zhang for their guidance in surgical procedure. We also thank Dr. Jianyun Zhang and Dr. Weidong Wang for their assistance with pathological analysis.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by National Natural Science Foundation of China [81100762, 81371162, 81671007, 81870781].