Female, 70 years old, with history of Merkel cell carcinoma now presenting with altered mental status, confusion. CT head at an outside hospital concerning for subependymal nodules within the periventricular regions. Extensive enhancing ependymal nodularity is seen involving the entire ventricular system, particularly the lateral ventricles. Marked T2 hyperintensity is also seen within the periventricular regions. The ventricles themselves are mildly enlarged. Some of the ependymal nodules demonstrate faint susceptibility effect, but no definite evidence of acute intracranial hemorrhage is seen. No abnormal fluid collections are detected. The basal cisterns remain patent.
Diffuse ependymal nodularity is seen most likely representing metastatic disease. The parenchyma surrounding the ventricles is edematous, and the ventricles and sulci are mildly enlarged.