[Intravascular lymphomatosis: diagnostic problems of a rare disease].

Intravascular lymphomatosis is a rare systemic disease characterized by proliferation of malignant B or rarely T lymphocytes. Skin and the brain are predominantly affected. We describe a patient presenting with focal neurological signs and progressive dementia. Cerebral neuroimaging findings were nonspecific. Postmortem examination revealed intravascular proliferation of atypical mononuclear cells in the lumens of small vessels in all organs. The authors conclude that diagnosis requires a high index of suspicion and pathological examination of the affected organs, but is rarely made ante mortem.