A 67-year-old man had a sudden onset of headache and aphasia, evolving to spontaneous improvement. A few months later, he developed dysarthria and left hemiparesis. Brain MRI showed several punctate lesions with perilesional edema, perivascular enhancement and restricted diffusion on DWI ([Figure 1]). PET-CT demonstrated mild uptake ([Figure 1]). Anatomopathological and immunohistochemical analysis were compatible with intravascular large B-cell lymphoma (IVL) ([Figure 2]). Treatment with R-CHOP and intrathecal methotrexate was established, with favorable response due to high tumor sensitivity[1]. Approximately half of IVL cases are diagnosed only after autopsy[2]. The main differential diagnoses are vasculitis, neurosarcoidosis, and ischemic stroke[3],[4].
Figure 1 Magnetic resonance imaging findings of intravascular lymphoma. (A and B) Fluid-attenuated inversion recovery axial images showed diffuse multiple hyperintensities of the cerebral white matter. (C and D) The perivascular curvilinear enhancement on T1-weighted imaging with gadolinium expanded markedly. (E and F) Diffusion-weighted imaging and apparent diffusion coefficient map showed restricted diffusion. (G and H) Perfusion magnetic resonance imaging (relative cerebral blood volume) and positron emission tomography - computed tomography were practically unremarkable.
Figure 2 Brain pathology showing small blood vessels filled with lymphoma cells and perivascular reactive lymphocytes (A and B). Immuno his to chemical staining showing CD20+ (C and D).
