Having to do with the two innermost meninges (thin layers of tissue that cover and protect the brain and spinal cord). Found on http://www.cancer.gov/dictionary?expand=L
Leptomeningeal: Having to do with the leptomeninges, the two innermost layers of tissues that cover the brain and spinal cord. Leptomeningeal metastasis refers to cancer that has spread from the original (primary) tumor to the leptomeninges. Found on http://www.medterms.com/script/main/art.asp?articlekey=40030