Extensive central nervous system involvement in optic pathway gliomas in neurofibromatosis type 1

Optic pathway gliomas (OPG) in neurofibromatosis type 1 (NF1) usually remain localized to the anterior visual pathway. However, a small number can demonstrate widespread dissemination. We describe three children with NF1 OPGs and extensive central nervous system involvement. In one case, a postmortem examination revealed tumor cells extending continuously from the optic nerves to the conus medullaris. This is the most widespread NF1 OPG reported in the literature. We suggest that rapid visual deterioration in the absence of radiographic changes or increased intracranial pressure can be caused by increasing tumor infiltration within the central nervous system.