Definition

A serious condition in which cancer cells spread from the original (primary) tumor to the meninges (the thin layers of tissue that cover and protect the brain and spinal cord). This can cause the meninges to become inflamed and cerebrospinal fluid and pressure to build up in the brain. Leptomeningeal metastasis can happen in many types of cancer, but it is most common in people with breast cancer, lung cancer, or melanoma. Also called carcinomatous meningitis, leptomeningeal carcinoma, leptomeningeal carcinomatosis, meningeal carcinomatosis, meningeal metastasis, and neoplastic meningitis.