Objective: Optic nerve glioma is a common finding in patients with neurofibromatosis type 1 (NF-1). Although dural ectasia of the optic nerve is encountered rarely, it has to be considered in the differential diagnosis.
Materials and methods: Three patients affected by NF-1 were examined sequentially by CT and MRI.
Results: Computed tomography demonstrated nonprogressing enlargement of the anterior optic pathways. Magnetic resonance imaging displayed widening of the perioptic dural sheath without any suggestion of tumor.
Conclusion: These findings are compatible with meningocele or dural ectasia of the optic nerve sheath. This entity represents a differential diagnosis to optic glioma in patients with NF-1.