Abstract

This 48-year female presented with a six-week history of increasingly aggressive, paranoid, and disorganized behaviour. Her past medical history was significant for a heart transplant one year prior, as well bilateral thromboembolic middle cerebral artery territory strokes with resulting global aphasia, cortical deafness, and cognitive dysfunction. Her neurological assessment upon admission was challenging due to significant baseline deficits, but it was noted that she was distractible and not following commands, yet had no new focal deficits. Neuroimaging (CT and MRI) demonstrated multiple ring enhancing lesions, predominantly located within the right temporal lobe, with significant surrounding vasogenic edema, which were thought to explain her subacute behavioural changes. A broad differential was considered, but given her
immunosuppressed status, an opportunistic infection or malignancy seemed most likely. She was started on broad spectrum empiric antibiotics, including coverage of protozoal and fungal organisms, and, given the diagnostic uncertainty, underwent brain biopsy.

What is/are?

1 : Most likely diagnosis based on H&E slide?