Ependymoma

This case shows a multilobulated T1 isointense, T2 FLAIR hyperintense heterogeneously enhancing mass centered in the fourth ventricle which extends through the foramina of Magendie and Luschka as well as through the foramen magnum. The differential diagnosis for a posterior fossa mass in a young patient includes juvenile pilocytic astrocytoma, medulloblastoma, and ependymoma. The imaging features in this case of a “soft” heterogeneous fourth ventricular tumor which squeezes through the foramina are characteristic of an ependymoma which was subsequently proven on pathology. The B-subtype which presents in older children and adults has a better prognosis than the A-subtype which presents most commonly in infants. Incidentally noted is what appears to be a small pars intermedia cyst of the pituitary on the sagittal post contrast images.