E-ISSN: 1019-5157
ISSN: 2651-5024
Case Report
Intraoperative Incidental Finding of Purely Intracranial Vagal Schwannoma in Microvascular Decompression for Hemifacial Spasm: A Case Report
Yan Xiao✉ ,
Yan Xiao ,
Bin Xu ,
Jing Liu ,
Xiaodong Cai ,
Doudou Zhang
DOI: 10.5137/1019-5149.JTN.49822-25.2
Article in Press
Corresponding Author:
Yan Xiao (e18212723826@163.com)
Abstract
Objective: This case report describes an incidental intraoperative finding of a pure intracranial vagal schwannoma during microvascular decompression (MVD) for hemifacial spasm (HFS), a rare clinical scenario with minimal precedent in the literature.
Case Description: A 67-year-old woman presented with a 10-year history of left HFS refractory to conservative management, prompting MVD as the next step. Preoperative magnetic resonance imaging (MRI) revealed neurovascular compression at the facial nerve root exit zone but failed to detect a small (1.7 mm) vagal schwannoma due to its small size and the lack of contrast-enhanced imaging. During a retrosigmoid infrafloccular approach, a tumor arising from a single caudal rootlet of the vagus nerve was identified. The involved rootlet was sacrificed, and gross total resection was achieved without intraoperative hemodynamic instability. Histopathological examination confirmed the diagnosis of schwannoma (S100+, SOX-10+). The patients facial spasm resolved completely after surgery, with no neurological deficits observed at the 1-year follow-up.
Conclusion: This case demonstrates that small intracranial vagal schwannomas may be undetectable on noncontrast MRI and discovered incidentally during MVD. Sacrifice of a single caudal vagal rootlet can be well tolerated without any cardiovascular or neurological consequences, underscoring the importance of meticulous dissection, intraoperative monitoring, and detailed knowledge of vagal rootlet functional topography.
Case Description: A 67-year-old woman presented with a 10-year history of left HFS refractory to conservative management, prompting MVD as the next step. Preoperative magnetic resonance imaging (MRI) revealed neurovascular compression at the facial nerve root exit zone but failed to detect a small (1.7 mm) vagal schwannoma due to its small size and the lack of contrast-enhanced imaging. During a retrosigmoid infrafloccular approach, a tumor arising from a single caudal rootlet of the vagus nerve was identified. The involved rootlet was sacrificed, and gross total resection was achieved without intraoperative hemodynamic instability. Histopathological examination confirmed the diagnosis of schwannoma (S100+, SOX-10+). The patients facial spasm resolved completely after surgery, with no neurological deficits observed at the 1-year follow-up.
Conclusion: This case demonstrates that small intracranial vagal schwannomas may be undetectable on noncontrast MRI and discovered incidentally during MVD. Sacrifice of a single caudal vagal rootlet can be well tolerated without any cardiovascular or neurological consequences, underscoring the importance of meticulous dissection, intraoperative monitoring, and detailed knowledge of vagal rootlet functional topography.
Keywords
vagal schwannoma
microvascular decompression surgery
hemifacial spasm
incidental finding