(though, the perinuclear halo on permanent sections is an artifact of tissue drying; fresh tissue lacks this characteristic "fried egg" appearance). They appear as a monotonous population of mildly enlarged round cells infiltrating normal brain parenchyma and producing vague nodules. Although the tumor may appear to be vaguely circumscribed, it is by definition a diffusely infiltrating tumor.

Classically they tend to have a vasculature of finely branching capillaries