A primary T-cell lymphoma of the central nervous system was diagnosed at autopsy in a 73-year-old woman. The course of the illness was made of multiple neurological episodes: hypersomnia, palsies of cranial nerves, aphasia, hemiparesis, epileptic fits during 4 years, with fast recoveries under corticosteroid therapy. CT scan and MRI abnormalities were also dramatically improved by the treatment.