Exceptional symptomatology of a lipoma beneath the third ventricular floor and successful neuroendoscopic treatment.

The aim of this paper is to present the exceptional case of a lipoma located beneath the floor of the third ventricle in front of right mamillary body manifesting with psychiatric symptoms and treated by navigated neuroendoscopy. A 58-year-old male was referred for neurosurgical treatment because of paroxysmal disturbances of consciousness accompanied by aggressive behaviour. Because electroencephalographic evaluation failed to confirm the epileptic origin of the presenting symptoms, the final psychiatric diagnosis was syndrome of amentia. However, when the MRI investigation revealed two tiny lipomas with one of them located in front of the right mamillary body, a hypothesis was established that this lipoma might be the cause of the clinical symptoms. After a thorough analysis of the patient's symptoms and taking into special consideration the functional role of hypothalamic structures the decision to remove the lipoma endoscopically was accepted. After stereotactic planning and functional correlation using digital stereotactic atlases, the lipoma located in front of the right mamillary body was endoscopically removed. The clinical course after navigated neuroendoscopic surgery proved complete disappearance of symptoms and problems supported by the results of imaging techniques, psychological investigations and neurological findings. Detailed anatomic analysis with pathophysiological consideration substantiated the excellent result of minimally invasive endoscopic surgery for lipoma removal.