Leukemia infiltrating the central nervous system structures. The disease is central nervous system leukemia (MONDO_0001606). Also known as: CNS leukaemia, CNS leukemia, central nervous system leukaemia (disease), central nervous system leukemia (disease), leukaemia (disease) of central nervous system, leukaemia of CNS, leukaemia of central nervous system, leukaemia of the CNS.