What is the differential for this lesion?
Left trigonal cystic lesion is most likely non-neoplastic (such as a intraventricular arachnoid, ependymal, noncolloid neuroepithelial or giant choroid plexus cyst).
Can the aforementioned cysts be distinguished?
Not on imaging, at least not with any degree of certainty. Histological examination of the wall of the cyst is required.
Thin walled cyst (blue arrows) is in the trigone of the left lateral ventricle, with dilatation of the occipital horn (OH) and temporal horn (TH) suggesting a degree of outflow obstruction.