[Incidence of vestibular schwannoma in Denmark].

INTRODUCTION

During the last 30 years the number of diagnosed vestibular schwannomas (VS) has increased from 15 in 1976 to 116 in 2006. The aim of this study is to describe and analyse this increase.

MATERIALS AND METHODS

In Denmark, the handling of VS patients has been centralised since 1976. Since 1976, 2046 new cases of unilateral VS have been diagnosed.

RESULTS

In 1976, 15 VS were diagnosed. Since then, the number of diagnosed tumours has increased almost linearly to 116 in 2006. The size of the diagnosed tumours has decreased from 35 mm in 1979 to 10 mm in 2006. In the beginning of the period, giant tumours dominated in contrast to the end of the period where the small tumours dominated. The mean age at the time of diagnosis has been slowly increasing from 50 years in the beginning to almost 60 years at the end of the period.

CONCLUSION

With easier access to MRI, vestibular schwannomas are found earlier when they are still small. The increase in the number of diagnosed tumours is mainly explained by the diagnosis of intrameatal and small tumours in the older age group which was not previously offered MRI examination.