Dementia and leukoencephalopathy due to lymphomatosis cerebri

Abstract

Lymphomatosis cerebri (LC) is a rare variant of primary central nervous system lymphoma (PCNSL). Clinically, the disease typically presents with a rapidly progressive dementia and unsteadiness of gait. Its presentation on cerebral MRI, which is characterised by diffuse leukoencephalopathy without contrast enhancement, often causes diagnostic confusion1 with suspected diagnoses ranging from Binswanger's disease to leukoencephalopathy or encephalomyelitis. Here we report a patient with subacute dementia and diffuse bilateral white matter changes in the cerebral hemispheres and additional involvement of the brainstem, basal ganglia and thalamus on MRI. Initially, she was considered to suffer from an autoimmune encephalitis, transiently responded to immunosuppression but then developed multiple solid appearing cerebral lymphomas.

Figure 1. (A–C) Cerebral MRI at admission.

(A, B) Fluid attenuated inversion recovery (FLAIR) weighted images showing pathological signal hyperintensities in the deep white matter of both hemispheres and the basal ganglia. (C) T1 weighted image with gadolinium (GD) application at the corresponding plane to B showing absence of contrast enhancement in the parenchyma with only an enhanced vessel. (D–F) Cerebral MRI 18 days later revealed a prominent increase in signal hyperintensities in FLAIR weighted images (D, E) now also involving the thalamus but still lacking contrast enhancement after GD (F). (G, H) Statistical parametric mapping analysis of cerebral fluor-desoxy-glucose-positron emission tomography (FDG-PET) at the planes corresponding to D and E showing increased FDG uptake (red) in the deep cerebral white matter. (I) Cerebral T1 weighted MRI 4 months later showing multiple nodular contrast enhancing lesions.