Male, 67 years old, with mesothelioma, being treated with PD1 antibody, presenting with an episode of encephalopathy. Confluent T2 hyperintensity seen within the periventricular white matter with scattered additional foci in the subcortical white matter and brainstem. None of these lesions is associated with restricted diffusion. There is no pathologic intracranial enhancement. No evidence of parenchymal edema or mass effect is seen. The ventricles and sulci are proportionately prominent compatible with underlying volume loss. No evidence of acute intracranial hemorrhage or any abnormal extra-axial fluid collection is seen. Scattered small foci of susceptibility in the bilateral cerebral hemispheres may reflect tiny chronic microhemorrhages.
1.No evidence of any active inflammatory or neoplastic process is seen intracranially.2.Findings are noted which may reflect chronic microvascular ischemia.