0 Optic glioma

Which one of the following statements is incorrect about Optic glioma?
A. Has a peak incidence in first decade
B. Arises from oligodendrocytes
C. Causes meningeal hyperplasia
D. Is associated with type I neurofibromatosis

ANSWER:

Ans : B
1. disease of childhood and most patients present before the age of 10
2. associated with type I neurofibromatosis in 60% of patients
3. present with decreased vision, proptosis or strabismus
4. tumour is fusiform in appearance and causes optic foramen enlargement
5. slow growing tumour
6.histologically, presence of pilocystic (hair-like) tumour cells (astrocytoma) and Rosenthal fibres. Cystic spaces may be present.
7.may be confused with meningioma as it can extend into the meninges causing meningeal hyperplasia