leukemia which has spread to the meninges or covering of the brain and spinal cord. Infiltration of the meninges by leukaemic cells, a common occurrence in relapsefollowing systemic administration of chemotherapeutic agents to leukemia patients.
Acute lymphocytic leukemia cells often collect in the lining of the spinal cord and brain, called the meninges. If not treated, the meninges can harbor leukemia cells, and relapse can occur in this site (meningeal leukemia ).