Neurofibromatosis type 2 diagnosed in the absence of vestibular schwannomas. A case report and guidelines for a screening protocol for children at risk

A 5-year-old girl presented with multiple tumours of the central nervous sy stem. As on the first MRI scan bilateral vestibular schwannomas were not de tected due to their small size, she initially did not meet the criteria for neurofibromatosis type 2 (NF2), although her clinical symptoms were highly suggestive for the diagnosis. Using molecular studies, a mutation in the N F2 gene was found confirming the clinical suspicion at an early age and ind icating the value of molecular analysis. Follow-up MRI 3 years later demons trated bilateral vestibular schwannomas more clearly, since they had increa sed in size. Conclusion In children, magnetic resonance imaging can be inconclusive for the diagnosis of neurofibromatosis type 2, since very small vestibular schw annomas may be missed. In these cases molecular studies may provide additio nal evidence for the diagnosis. We propose guidelines for a screening proto col for children at risk for having neurofibromatosis type 2.