is a type of non Hodgkin Lymphoma, generally composed with B cells, its ocurrence is infrequent, clinically progressive and has a fatal course. Vascular damage is related with tumoral infiltration and small caliber occlusion, with results in multi infarcts. Neurological symptoms and signs are frequently the first clinical manifestation, which include sub acute encephalopathy, cognitive impairment, delirium, aphasia, hemipharesis, visual disturbances, paraplegia, paresthesia and cranial nerves involvement. MRI shows images of vasculitis from CNS. Cerebral Intravascular Lymphomatosis must be considered in differential diagnosis of rapid and subacute dementias, and clinical cases with small vessel recurrent multi infarct of unusual etiology. We present the clinical case of a patient with rapid progressive dementia and systemic disease manifestation. The CNS involvement was characterized as a subacute encephalopathy, with confusion and agitation, seizures, motor disturbances, bilateral plantar extensor reflexes and cerebellar signs. The clinical symptomatic course was progressive, with weight loss and fluctuant fever. The patient had a fatal course after he was treated with Methylprednisolone. Postmortem pathologic examination revealed a diffuse non Hodgkin lymphoma of B cells, intravascular variant, with brain compromise, cerebellum, suprarenal glands, pancreas, myocardium, thyroid gland, lung kidney and the lever.
