 There is a 7 x 8 mm mass within the inferior fourth ventricle centered at the obex that demonstrates slightly different signal characteristics than the adjacent brain parenchyma and does not have the appearance of choroid plexus. There is no evidence of intracranial hemorrhage or acute infarct. There is a single nonspecific punctate focus of T2 hyperintensity within the left periventricular white matter that likely represents age-related white matter changes. The ventricles are somewhat prominent, out of proportion to the degree of mild volume loss. There is no midline shift or herniation. The major cerebral flow voids are intact. There is a prominent cisterna magna. There is a retention cyst within the left maxillary sinus. The midline structures and craniocervical junction are within normal limits.
8 mm mass centered at the obex, in the context of mild ventriculomegaly, is very suggestive of subependymoma with other etiologies such as ependymoma or a choroid plexus lesion also possible. Postcontrast sequences are recommended for further characterization.This finding was called by Dr. Michael Rozenfeld to Dr. Andrea Dellaria on 5/9/2015 12:35 PM.