Neurofibromatosis type 1 (NF1)

Children with NF1 have an increased propensity to develop low-grade gliomas, especially in the optic pathway. Up to 20% of patients with NF1 will develop an optic pathway glioma. Most children with NF1-associated optic nerve gliomas are asymptomatic and/or have nonprogressive symptoms and do not require antitumor treatment. Screening magnetic resonance imaging (MRI) in asymptomatic patients with NF1 is usually not indicated, although some investigators perform baseline MRI for young children who cannot undergo detailed ophthalmologic examinations.[6]

The diagnosis is often based on compatible clinical findings and imaging features. Histological confirmation is rarely needed at the time of diagnosis. When biopsies are performed, these tumors are predominantly pilocytic astrocytomas.[7]

Indications for treatment vary and are often based on the goal of preserving vision.

Very rarely, patients with NF1 develop high-grade gliomas. Sometimes, this tumor is the result of a transformation of a lower-grade tumor.[8]