Presentation
Nausea and vomiting
Patient Data
A hyperdense mass is seen in the fourth ventricle, obstructing the ventricle and causing hydrocephalus.
A T2W intermediate signal intensity mass in the fourth ventricle, with extension from Luschka and Magendie foramina into the right cerebellopontine (CP) angle and cervicomedullary junction, respectively.
On postcontrast images there is heterogenous enhancement within the lesion.
Obstruction of the quadrigeminal cistern and mild mass effect on the posterior midbrain represents upward extension of the mass.
Case Discussion
Medulloblastoma and ependymoma are two important differential considerations in the pediatric fourth ventricular masses.
Tumoral heterogeneity, origin from the floor of the fourth ventricle, heterogeneous enhancement, and extension through ventricular foramina into the adjacent cisterns are features in favor of ependymoma.