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.

Case report

This 65-year-old woman had a history of insidious personality changes and forgetfulness of several months. Shortly before admission she developed double vision. Neurological examination revealed bilateral sixth nerve palsy. Neuropsychological examination showed mild dementia. CSF examination showed an increased protein level (931 mg/l; normal 150–400) and cell count (18/μl; normal <4). On cytology, many activated lymphocytes but no malignant cells were found. There was IgM synthesis and positive oligoclonal bands in the CSF. Serum levels of β2-microglobulin were normal (2.0 mg/l) and CSF levels were increased to 3.37 mg/l (normal <3). Antinuclear antibody titres (1:320; normal <1:80) and circulating …