Spontaneous Vestibular Schwannoma Regression: A Case-Control Study.

OBJECTIVE: To explore the nature of spontaneously regressing vestibular schwannomas (VS) and identify possible predictive factors for such behavior. STUDY DESIGN: Retrospective case control study. SETTING: Tertiary referral center, university teaching hospital. PATIENTS: Patients with sporadic VS demonstrating spontaneous regression compared with a control group of patients with growing VS. INTERVENTIONS: Review of serial magnetic resonance imaging of the internal auditory meatus (MRI IAM) and case notes and direct comparison of possible related factors between the two groups using univariate analysis. MAIN OUTCOME MEASURES: Presenting symptoms, VS size and consistency, patients' age and sex, tumor laterality and location, and the neutrophil-to-lymphocyte ratio between the two groups. RESULTS: Of the 540 patients on the database 28 (5.2%) showed spontaneous regression with a mean follow-up of 122 months. Mean absolute and relative regression was 3.9 mm and 25.7%, respectively. 60% of tumors showed gradual regression while 25% showed growth followed by regression. Regressing VS had a significantly larger size than the control group; while the regressing tumors were located further from the fundus than the control group. The remaining examined factors did not reach a statistical level of significance. CONCLUSION: This is, to our knowledge, the first study comparing a cohort of regressing tumors with a control group of growing VS. The finding that the location of tumors around the porous, is more common in regressing VS has implications for patients' counselling.

Neutrophil to Lymphocyte Ratio as a Predictive Marker of Vestibular Schwannoma Growth.

OBJECTIVE: To examine the predictive value of neutrophil to lymphocyte ratio (NLR) for vestibular schwannoma (VS) growth. STUDY DESIGN: Retrospective case-control study. SETTING: Tertiary, referral center. PATIENTS: Patients with sporadic VS and available NLR obtained within 1 year from the diagnosis were divided into two groups with growing or non-growing tumor. Patients with known conditions affecting NLR were excluded. INTERVENTIONS: NLR and tumor growth as determined by linear measurements on serial magnetic resonance imaging. MAIN OUTCOME MEASURES: VS growth, demographic factors, and NLR were compared using multi-variant logistic regression and Receiver Operating Characteristic (ROC) curve analysis. RESULTS: A total of 161 patients fulfilled the inclusion criteria, 79 with growing VS (men:women ratio = 43:36, mean age, 61.8 years) and 82 with non-growing tumors (men:women ratio = 37:45, mean age, 64.9 years). Mean NLR for the group with growing VS was 3.34 (SD [standard deviation] = 1.5) and 2.31 (SD = 0.76) for the group with non-growing VS (p = 0.001; 0.03 when adjusted for all parameters). The optimal cut-off point was NLR = 3.05 with positive predictive value 83.8% and 100% for NLR greater than 5.3. ROC analysis of the adjusted data for age, sex, and side, gave an area under the curve of 0.768, indicating NLR as a good independent predictive marker. Interestingly, the size of tumor was statistically significantly higher for the growing VS group (p = 0.001). CONCLUSION: Despite the low specificity of low NLR, our results indicate high NLR as a good predictive marker for VS growth. Confirmation by prospective studies will have a significant impact on patients' management.