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. QUESTION What causes tooth decay? See Answer From Healthy Resources 10 Rheumatoid Arthritis SymptomsWhat Is Exocrine Pancreatic Insufficiency?Truth About Vitamin B12 Featured Centers What Are the Best PsA Treatments for You?Understanding Biologics 10 Things People With Depression Wish You Knew Health Solutions From Our Sponsors Shot-Free MS Treatment Your Child and COVID-19