Most gliomas in neurofibromatosis type 1 (NF1) are pilocytic astrocytomas (PAs) of the optic pathway occurring in young children. However, some individuals develop gliomas that lack the typical NF1-associated clinical features or radiographic appearance. We identified 17 atypical presentations from a review of 100 patients with NF1-associated gliomas. Biopsy showed that 9 were not classic PAs. These data highlight the value of biopsy in NF1-associated gliomas with unusual clinical or radiographic presentations.