Management of hydrocephalus in children with posterior fossa tumors

Case 1: A 2-year-old male with no prior medical history presented to the emergency room with a 3-week history of constant headache and daily vomiting. Computed tomography (CT) and subsequent magnetic resonance imaging (MRI) of the brain [Figure 1] showed a minimally enhancing mass in the fourth ventricle, which extended out through the foramen of Luschka on the left. There was associated supratentorial hydrocephalus. He had no evidence of spinal metastasis on MRI of the spine. There was no papilledema on the fundoscopic exam. He underwent placement of a right frontal external ventricular drain (EVD) and gross total resection of the tumor through a modified telovelar approach at the same time. The pathology was consistent with a grade II ependymoma. Postoperatively, the ventricular drain was unable to be weaned, and he underwent ventriculoperitoneal shunt placement without complication 1.5 weeks after initial surgery. He was eating and ambulatory after recovery. He went on to radiation therapy. Figure 1 Magnetic resonance images of patient described in case 1. (a) Sagittal precontrast. (b) Axial fluid-attenuated inversion recovery. (c) Axial postcontrast Case 2: A 9-year-old male with no prior medical history presented to an outside hospital emergency room with 2 weeks of progressive headaches and 1-day of vomiting. A CT of the head showed a posterior fossa mass. MRI of the brain [Figure 2] showed an enhancing fourth ventricular tumor with associated metastatic lesions throughout both cerebellar hemispheres and supratentorial hydrocephalus. There was no evidence of spinal metastasis. Fundoscopic exam was positive for papilledema. He underwent placement of a right frontal EVD and resection of the fourth ventricular mass through a modified telo-velar approach at the same time. The infiltrative lesions in the cerebellum were not resected. The pathology was consistent with medulloblastoma. Postoperatively, his EVD was weaned over the course of 2 weeks and removed. He did not require permanent cerebrospinal fluid diversion. He was discharged home after recovery and went on for adjuvant radiation therapy. Figure 2 Magnetic resonance images of patient described in case 2. (a) Sagittal precontrast. (b) Axial fluid-attenuated inversion recovery. (c) Axial postcontrast