The vast majority of central neurocytomas are located entirely within the ventricles, most within the lateral ventricles around foramen of Monro. Tumours with extension into the third ventricle or a purely third ventricular location are also encountered. Extra-ventricular tumours (aka cerebral neurocytomas) are rare.
The patient went on to have a craniotomy and excision of the mass which confirmed the diagnosis of a central neurocytoma.