Case Notes
History
15 yo male with 1 week of severe headache, vomiting and blurred visionExam
MR flair
Prior Study
Noncontrast T1-w MR and T2-w spin-echo MR1. Nonaggressive appearing, large mass arising from the septum pellucidum in the body of the left lateral ventricle with inferior extension into the upper portion of the 3rd ventricle where it obstructs CSF flow at the iter portion of the cerebral aqueduct. The most likely pathologic consideration is central neurocytoma.
2. Grade 1.8/4 ventricular enlargement, which lacks transependymal fluid migration, and therefore despite the size of the lateral ventricles, this is not an acute progressive form of hydrocephalus. But rather this is a compensated form of hydrocephalus. Whether it is arrested or slowly progressive is indeterminate on a single exam.
3. There is a single small drop met in the right lateral ventricle.
Sagittal post contrast MR
1. There is an intraventricular, benign appearing mass arising from the septum pellucidum (likely neurocytoma). The bulk of the lesion is within the body of the left lateral ventricle and in the upper (thalamic portion) of the 3rd ventricle. The lateral vents are blocked at the foramina of Monroe, while the lower 3rd vent is blocked at the iter (i.e. the entrance to the cerebral aqueduct).
2. This is a compensated (either arrested or slowly progressive) form of grade 1.8/4, hydrocephalus without appreciable raised intracranial nor intraventricular pressure.
3. There is early central downward transtentorial herniation of the dilated lower 3rd ventricle.