• A serious problem that may occur in cancer in which cancer cells spread from the original (primary) tumor to the meninges (thin layers of tissue that cover and protect the brain and spinal cord). It can happen in many types of cancer, but is the most common in melanoma, breast, lung, and gastrointestinal cancer. The cancer may cause the meninges to be inflamed.
  NCI Dictionary of Cancer Terms
  U.S. National Cancer Institute, 2021
• Diffuse spread of cancer to the meninges.
  NCI
  U.S. National Cancer Institute, 2021
• Primary or secondary neoplasm in the ARACHNOID or SUBARACHNOID SPACE. It appears as a diffuse fibrotic thickening of the MENINGES associated with variable degrees of inflammation.
  NLM Medical Subject Headings
  U.S. National Library of Medicine, 2025
• Leptomeningeal carcinomatosis (LC), also termed neoplastic meningitis, is a serious complication of cancer that carries substantial rates of morbidity and mortality. It may occur at any stage in the neoplastic disease, either as the presenting sign or as a late complication, though it is associated frequently with relapse of cancer...
  Medscape
  WebMD, 2025