Fact-sheet: Cerebellar astrocytoma
Updated on 10/07/2017 at 9:51 AM
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Definition
Pilocytic astrocytoma: grade I glioma (WHO) classically occurring in children aged 3 to 10 years. Possible in adolescents and young adults.
Clinical features
Intracranial hypertension syndrome
CT
Hypodense cyst
Iso/hyperdense mural nodule
Nodular calcifications in 15% of cases
MRI
Well-circumscribed cystic lesion with mural nodule. Little perilesional edema. BRAIN Location = midline - optic nerves/chiasm (associated with NF type 1) -diencephalon -basal ganglia -cerebellum -brainstem -floor of the third ventricle Cystic component with signal close to CSF (T1 hypointense, T2 hyperintense). Mural nodule iso-to-hypointense on T1, iso-to-hyperintense on T2, with intense and heterogeneous enhancement. Enhancement may extend along the cyst walls. More rarely: solid component occupying nearly the entire cyst (difficult differential diagnosis with cerebellar medulloblastoma/supratentorial glioblastoma) Perfusion = normal SPINAL CORD >50% of intramedullary tumors in children 40% of spinal glial tumors in adults (peak 30-40 years) Eccentric, poorly circumscribed cystic lesion Iso-to-hypointense on T1, hyperintense on T2 Moderate enhancement +/- syringomyelia above and below
Management
Surgery if resectable (90% of cases) => classic progression toward cure;
otherwise: radiotherapy/chemotherapy.
Spontaneous regression is possible along the visual pathways as well as within the parenchyma.
Classification
Grade I glioma (WHO)