Enhancing lesion identified centered over the inferior aspect of the fourth ventricle and posterior aspect of the medulla. Susceptibility correlates to the high-density material identified on CT which may be a combination of calcium and/or hemorrhage. The ventricular size remains age-appropriate. MRA (not shown) demonstrates no focal vascular abnormality. Several FLAIR hyperintense foci are identified within the deep white matter most in keeping with small vessels in the changes. No other focal lesions identified.
Mass lesion centered overlying the inferior aspect of the fourth ventricle causing mass effect on the poster aspect of the medulla has features most in keeping up with a tumor. With these appearances and in this location, ependymoma would be the most likely diagnosis.