[Rapidly progressive dementia associated with leukoencephalopathy: A case report of lymphomatosis cerebri].

Introduction: Lymphomatosis cerebri is a rare form of primary central nervous system lymphoma characterized by an atypical clinical presentation and neuroimaging, with a poor short-term prognosis.

Case Report: A 51-year-old woman began with clinical manifestations characterized by rapidly progressing cognitive impairment associated with a behavioral disorder, myoclonus, and gait disturbance. The brain magnetic resonance image showed extensive signaling in the bilateral periventricular white matter.