Clinical Factors Associated with Spontaneous Regression and Progression of Vestibular Schwannoma: An Exploratory Case–Control Study

Abstract

Abstract Objective Spontaneous regression of vestibular schwannoma (VS) is a rare and poorly understood phenomenon. This study aimed to identify clinical, radiographic, and lifestyle factors associated with spontaneous regression compared with tumors requiring surgical resection. Methods Patients demonstrating ≥ 2 mm spontaneous regression at a single tertiary center between 2001 and 2025 were compared to surgically treated controls exhibiting tumor progression. Imaging and clinical characteristics were reviewed, and participants completed a survey assessing demographics, medical history, viral history, and lifestyle factors. Results Eighteen spontaneous regression patients and 18 surgical control patients completed the survey. A higher proportion of spontaneous regression patients reported a history of oral herpes or varicella-zoster virus compared with surgical control patients (55% vs. 17%, p  = 0.035). Spontaneous regression patients reported fewer years of cellphone use prior to diagnosis (5 vs. 15.8 years, p  < 0.001). No radiographic features were predictive of spontaneous regression. Conclusion In this exploratory cohort, spontaneous regression of VS was associated with self-reported active herpes simplex virus/varicella-zoster virus expression, while patients with spontaneous regression reported fewer years of cellphone use than surgically treated controls. Larger prospective studies are required to clarify underlying mechanisms and identify reliable predictive markers.