Subependymal giant cell astrocytoma

Findings

Axial T2 weighted image demonstrates a well-marginated intraventricular mass near the foramen of Monro. The lesion is lobulated in appearance and is causing obstructive hydrocephalus. Associated vasogenic edema is noted extending into the left frontal lobe. Axial and Coronal T1 contrast-enhanced MR sequences demonstrate intense, heterogeneous enhancement of the mass.

Differential diagnosis:
- Astrocytoma
- Subependymoma
- Germinoma
- Choroid plexus tumor
- Hamartoma


Diagnosis: Subependymal giant cell astrocytoma


Key points

Subependymal giant cell astrocytomas are seen as an enhancing intraventricular mass in a patient with tuberous sclerosis complex. Subependymal giant cell astrocytomas occur in about 10 percent of patients with TS.
Almost always located near the foramen of Monro.
Well marginated, often lobulated
Heterogeneous, strong enhancement
Growth favors the diagnosis (vs static tuber).
Brain MR with contrast should be recommended every 1-2 years for followup.
FLAIR sequence is useful for detecting subtle CNS findings of tuberous sclerosis.
SGCTs are pathologically indistinguishable from subependymal nodules, and radiologic criteria for distinguishing the lesions are unreliable. Clinical criteria are therefore more useful in decision-making regarding operative therapy.