Neuroimages and Neuropathology of a stroke-like cerebral lymphomatoid granulomatosis.

A 70-year-old man presented to the Emergency Department reporting the acute onset of non-fluent aphasia, hyposthenia, and hemi-anesthesia of the right body. Brain computerized tomography revealed a subcortical hypodense lesion in the middle cerebral artery territory. Neck ultrasounds of internal and external carotid arteries and of the vertebral arteries showed a focal moderate stenosis of the left internal carotid artery due to a soft atheromasic plaque. These findings that were initially consistent with a diagnosis of an ischemic stroke were not confirmed by magnetic resonance (MR). The latter showed an hyperintense lesion on FLAIR and T2-weighted sequences located in the left centrum semiovale, corona radiata, and thalamus, with a well-defined regular rim and a mild compressive effect on the lateral ventricle, with diffusivity restriction but without ADC reduction and with a punctate and serpiginous gadolinium enhancement on T1 sequences (Figure 1). Within the first day of observation, the patient started complaining progressive mental deterioration, in absence of any other possible causes, and a total body CT scan excluded any other organ involvement. Patient was then referred to the neurosurgeon in order to perform a brain biopsy. The neuropathology was compatible with the diagnosis of cerebral lymphomatoid granulomatosis (LG) (Figure 1).