This mass given its characteristics was reported as a subependymoma of the lateral ventricle.

Subependymomas are rare benign intraventricular, with indolent growth and usually asymptomatic. It preferably located at the lateral ventricles and the fourth ventricle. Usually result from a incidental finding in imaging studies or autopsy. Rarely become  a symptomatic lesions.

It is important to distinguish from a central neurocytoma especially if located in the third ventricle or lateral ventricle.