[The role of leukemic conversion in the development of lymphoma infiltration of the nervous system].

On the basis of neuropathologic studies in 22 patients died from ML it was found that lymphoma cells in the brain and spinal cord were in the form of leukostasis, infiltrations usually limited to perivascular spaces, infiltrations in hemorrhagic foci and their vicinity. In cerebrospinal meninges, spinal roots and peripheral nerves we observed leukostasis and intraparenchymatous infiltrations. It was found that the most important role in the development of lymphoma infiltrations in the nervous system was played by hematogenic metastases whose development in the brain and spinal cord was promoted by leukemic conversion with high leukocytosis. In contrast, marked dissemination of lymphoma cells to peripheral blood is not indispensible for the development of infiltrations in the cerebrospinal meninges and peripheral nervous system.