Fig. 3

Intraoperative photographs of the mass resection procedure. a Intraoperative neuroendoscopy image showing the reddish lobular mass with hematoma and obstruction of the foramen of Monro. b Cavum septum pellucidum had already occurred because of the high intracranial pressure associated with hydrocephalus. c Insertion of clear plastic sheath (ViewSite) into the brain. d The mass was bluntly dissected from the ventricle wall by one surgeon. e Total en bloc resection of the mass was performed