Extracranial non-vestibular head and neck schwannomas: a case series with the review of literature

Abstract Introduction: Schwannomas are tumous that arise from Schwann cells. Schwannoma is one of the differential diagnosis for lateral neck swelling. Objective: In this study, we aim to describe the incidence, presenting clinical features and management of extracranial, non-vestibular schwannomas of head and neck region, along with the review of the literature. Methods: Patients treated at our tertiary care hospital for head and neck schwannomas for the past 15 years were included in the study. A review of literature on the extracranial head and neck schwannoma was also done. Results: Twenty-five cases were assessed in this study. Nineteen cases presented as a neck swelling during the initial evaluation. Vagus nerve was the most common nerve of origin, followed by the cervical sympathetic plexus. A rare presentation arising from brachial plexus C5 nerve root was also encountered. A few rare cases of schwannomas arose from the nasal cavity, paranasal sinuses, and oral cavity. Surgical excision was done in all the cases with histopathology suggestive of schwannoma. The nerve of origin of the tumor was identified in nineteen patients. Among them, 11 (58%) were from the vagus nerve, 7 (37%) from the cervical sympathetic chain, and 1 (4%) from the brachial plexus C5 nerve root. Conclusion: A long-standing unilateral neck mass is the most common presenting complaint in head and neck schwannoma. The diagnosis is mainly based on clinical features and investigations such as imaging. The mainstay of treatment is complete surgical excision. The diagnosis is confirmed on the histopathological study after excision of the lesion. Due to the proximity of the tumor with the involved nerve, palsy may occur. Hence, an accurate preoperative diagnosis of schwannoma is essential.

摘要 引言：神经鞘瘤（Schwannomas）是起源于雪旺细胞（Schwann cells）的肿瘤，颈侧肿胀的鉴别诊断中包含神经鞘瘤。目的：本研究旨在描述头颈部颅外非前庭神经鞘瘤的发病率、首发临床特征及诊疗方案，并结合文献复习进行分析。方法：纳入我院近15年收治的头颈部神经鞘瘤患者作为研究对象，同时开展颅外头颈部神经鞘瘤相关文献的回顾性研究。结果：本研究共评估25例病例。其中19例患者初诊时表现为颈部肿块。迷走神经是最常见的肿瘤起源神经，其次为颈交感神经丛；同时还观察到1例起源于臂丛C5神经根的罕见病例。另有少数神经鞘瘤起源于鼻腔、鼻旁窦及口腔。所有病例均接受手术切除治疗，术后组织病理学检查均证实为神经鞘瘤。其中19例患者明确了肿瘤起源神经：11例（58%）起源于迷走神经，7例（37%）起源于颈交感干，1例（4%）起源于臂丛C5神经根。结论：长期存在的单侧颈部肿块是头颈部神经鞘瘤最常见的首发主诉。该病的诊断主要基于临床特征及影像学等检查手段，治疗的核心方案为完整手术切除。术后通过组织病理学检查可明确诊断。由于肿瘤毗邻受累神经，术后可能出现神经麻痹，因此术前准确诊断神经鞘瘤至关重要。