Risk factors associated with vestibulocochlear nerve schwannoma: systematic review

The vestibulocochlear nerve schwannoma (VS) is a benign tumor that stems from the edge of the Schwann's sheath. It is considered the most frequent intracranial benign tumor, of low lethality rate and unknown etiology. AIM: to identify risk factors associated with VS. STUDY DESIGN: systematic review. METHODS: electronic search of studies using the following key words: “risk”, “schwannoma”, “vestibular”, “neuroma” and “acoustic”. All original articles on epidemiological studies published in Portuguese, English or Spanish describing measures of association were included. RESULTS: twenty case-control studies were found, most of them published in the United States. The analysis of those studies shows educational level, household income, occupation, exposure to ionizing radiation and noise, allergic diseases as well as the use of both cellular and cordless phones as risk factors for the VS. CONCLUSION: methodological limitations and lack of precision in the findings impose limits to definitive conclusions concerning those risk factors. The current study contributes with information which can subsidize decisions related to the methodology to be used, having in mind new investigations on risk factors for VS. Therefore, it is of great help for knowledge improvement in this field.