MRI diagnosis of NF-1 in children without café-au-lait skin lesions.

Three of ten children with optic gliomas satisfy the 1987 National Institutes of Health consensus criteria for neurofibromatosis type 1 (NF-1). The diagnosis in these cases is based on the presence of café-au-lait skin lesions in addition to the optic glioma. Two children without skin lesions have typical findings on magnetic resonance imaging (MRI) that also suggest a diagnosis of NF-1. A review of 281 NF-1 children with brain MRI results demonstrates the presence of these abnormalities in 57% of the cases. It is suggested that this MRI abnormality is sufficiently specific to add this feature to the list of diagnostic criteria. When MRI findings are present in a child with optic glioma and without skin lesions, counseling should be given for NF-1. It is noteworthy that these typical MRI findings in NF-1 are less common in adulthood, apparently because of spontaneous resolution.