[Neurofibromatosis type 1 and optic pathway gliomas. A series of 80 patients]

From a series of 530 patients with neurofibromatosis type 1 (NF1), we performed a retrospective assessment of the long-term neurologic, visual, neuroimaging and evolution of 80 patients (15%) with optic pathway gliomas (OPG). All the 80 patients, 58 (72.5%) females and 22 (27.5%) males were diagnosed during childhood (below age 16 years), range 13 months to 15 years (average: 4.6 years).

Image studies showed the distribution of the lesions among optic nerves, chiasm, tracts and radiations demonstrated that only 25% of the tumors involved only one optic nerve and 11.5% were located only in the chiasm, while 40% involved one or both optic nerves and chiasm, tracts and radiations. Two patients showed pilocytic astrocytoma in the histological study. Late diagnosis (after 7 years of age) of OPG was made in three patients and late progression was evident in three others who required surgical resection, radiotherapy or chemotherapy.

All patients were diagnosed during childhood (below 16 years of age). Incidence was double in girls than in boys. Despite the apparent tumoral agressivity of the magnetic resonance and magnetic resonance spectroscopy images, histological findings corresponded to benign pilocytic astrocytoma. Some tumors follow the growth after 7 years. Continued monitoring of patients with NF1 into adulthood is advisable.