[Infiltration of central nervous system and meninges in lymphomas with leukemic conversion].

The cases of four patients with lymphoma with leukemic conversion, who exhibited neoplastic infiltration of the central nervous system and of the meninges are reported. The anatomo-pathologic study showed the presence of small nodules of leukemic cells, in two patients. The other two patients had clinical improvement after the use of metotrexate by spinal route so that the anatomopathologic study of their CNS and meninges showed no abnormality.