What should be done in the event of incidental meningioma?

Background and purpose. - The growing use of magnetic resonance and computed tomography imaging has facilitated the diagnosis of brain tumours even before the presence of clinical signs. A significant proportion of incidental lesions identified will be meningiomas, i.e. more than 40% of the diagnosed meningiomas are not associated with clinical signs. The natural history of incidental asymptomatic intracranial meningiomas must be known to develop the optimal therapeutic strategy: what is the tumor growth rate? How many asymptomatic tumours eventually become symptomatic? Method. - The literature was reviewed in an attempt to answer these questions. Results.- In cases of incidental meningioma, its location, size and radiological aspect, the patient's age, the eventual unknown symptoms and the multiplicity of the lesions must all be considered. The radiological characteristics associated with low tumoral growth rate are the existence of calcifications and hypointense regions on T2-weighted MR images. On the radiological aspect, more than 60% of asymptomatic meningiomas will not grow in size. However, some meningiomas, even small in size, must be treated because of their location or the risk of producing neurological deficits. Conclusion. - We recommend neurosurgical consultation for all patients with an incidental meningioma. (C) 2011 Elsevier Masson SAS. All rights reserved.