Go Back Brain/15. Brain and meninges, Infratentorial/Neoplasm, Neoplasm-like condition/15.3 - Juvenile Pilocytic Astrocytoma/ Go to Index

Most common infratentorial neoplasm in pediatric age group

Less common locations:

Chiasm/hypothalamus/floor of 3rd ventricle

Cerebral hemisphere

Thalamus

Spine.

Excellent prognosis with complete resection (5 year survival rate > 90%)

Peak incidence in 1st decade

Associated with NF-1

Usually associated with anterior visual pathway and can be multicentric.

Typically demonstrates conspicuous cyst (> 66%) with vascular tumor nodule in wall

Chiasmal/hypothalamic tumors less commonly have macroscopic cysts

Usually well circumscribed; leptomeningeal dissemina-tion rare.

Imaging:

Nodule can be isointense to markedly hyperintense to brain on T2

Absence of adjacent brain edema or intratumoral Ca++

Hemorrhage rare

Nodule usually strongly enhances.