Per EPIC, recent diagnosis of acute mixed lineage (T/myeloid) leukemia c/b hyperleukocytosis s/p leukophoresis at OSH, DIC (resolved) who received debulking dexamethasone/vincristine and now receiving induction chemo with CALGB, presents with lethargy and altered mental status concerning for CNS involvement or meningitis. There is redemonstration of ependymal enhancement along the right frontal horn, and right greater than left occipital horns of the bilateral ventricles with associated diffusion restriction, most likely representing ependymitis/ventriculitis with debris/pus in the right ventricle. There is increased T2/FLAIR signal hyperintensity associated with the right periventricular white matter. There is a peripheral nodular enhancing lesion in the left cerebellar hemisphere measuring 11 x 7 mm with associated central restricted diffusion and decreased surrounding T2/FLAIR signal hyperintensity, most likely representing an abscess. There is leptomeningeal enhancement involving the surface of the bilateral left greater than right cerebellar hemispheres. There are scattered punctate foci of susceptibility artifact, likely representing hemosiderin deposition from chronic microhemorrhages. Direct comparison to prior MRI is limited due to motion artifact, but they appear to be present.There is no evidence of intracranial hemorrhage or acute infarct. The ventricles and basal cisterns are unchanged in size and configuration. There is no midline shift or herniation. The skull and extracranial soft tissues are unremarkable.
1. Peripheral nodular enhancing lesion within the left cerebellar hemisphere with central restricted diffusion, most favored to represent an abscess, with less prominent surrounding edema. Additional prominent enhancement of the bilateral ventricular walls containing debris/pus, most suggestive of ventriculitis, although some of this enhancement may be related to leukemic involvement. Leptomeningeal enhancement of the left greater than right cerebellum surfaces, which may be related to meningitis although again some of this may be related to leukemia. Sampling of the CSF may be considered for further evaluation. 2.Multiple chronic microhemorrhages, which are also present on prior motion degraded exam, are nonspecific but given history can be seen with DIC.