Rosette-forming glioneuronal tumor: report of a chiasmal-optic nerve example in neurofibromatosis type 1: special pathology report

Neurosurgery. 2009 Apr;64(4):E771-2; discussion E772. doi: 10.1227/01.NEU.0000340979.81362.F3.


Objective: Rosette-forming glioneuronal tumor is a rare, rather recently described tumor featuring a highly distinctive, biphasic histological pattern, including a cytologically uniform neuronal component of Homer-Wright type pseudorosettes and an accompanying astrocytic element resembling pilocytic astrocytoma. Its occurrence in the posterior fossa and association with the fourth ventricle is stereotypical and a feature of all reported cases.

Clinical presentation: In this article, we describe the first rosette-forming glioneuronal tumor arising outside this site, a histologically classic example involving the anterior visual pathway and associated with neurofibromatosis type 1.

Intervention: Genetic (fluorescent in situ hybridization) studies demonstrated no large deletion in either normal or neoplastic tissue, indicating that the genetic abnormality underlying neurofibromatosis type 1 in this patient is likely a very small deletion or point mutation.

Conclusion: The relation of the tumor to the underlying neurofibromatosis type 1 cannot be assessed.

Publication types

  • Case Reports

MeSH terms

  • Astrocytoma / pathology
  • Humans
  • Magnetic Resonance Imaging / methods
  • Male
  • Neurofibromatosis 1 / pathology*
  • Optic Chiasm / pathology*
  • Optic Nerve Neoplasms / pathology*
  • Young Adult