= rare benign thin-walled cyst
Cause: sequestration of developing neuroectoderm during embryogenesis
Histo: thin-walled ependyma-lined cyst containing clear serous fluid
Location: lateral ventricle, juxtaventricular in temporoparietal region + frontal lobe; rare in subarachnoid space, brainstem, cerebellum
Site: along choroid fissure
DDx: choroid plexus cyst (NOT of CSF signal intensity on all sequences, typically bilateral), arachnoid cyst (in arachnoid spaces), neurocysticercosis (hyperintense rim on FLAIR), asymmetric ventricles