Posterior fossa tumour

WHO Grade

Percentage of All CNS Tumors

Location of Tumor

Imaging Characteristics

5-Year Overall Survival

Recommended Treatment

I

2.10%

Vermis = hemispheres

Well circumscribed, contrast enhancing; often with cystic formation and mural nodule

85%–100%

GTR

IV

1.50%

Hemispheres > vermis

Variable definition, variable enhancement; may have cystic or necrotic foci

64%–84%

GTR plus craniospinal XRT with posterior fossa boost

II

N/A

Hemispheres > vermis

Minimal heterogeneous enhancement; mottled areas of hyperintensity

N/A

GTR

I

0.80%

Hemispheres > vermis

Intense enhancement, flow voids; solid or cystic with mural nodule

>50%

GTR with close follow-up and screening for VHL

I

N/A

Hemispheres

CT—low density with occasional calcifications; MR—“tiger stripe” nonenhancing

N/A

GTR with screening for Cowden syndrome