Meningeal carcinomatosis is a medical condition that refers to the spread of cancer cells to the meninges, which are the membranes that surround the brain and the spinal cord. This condition can cause a variety of symptoms, such as headaches, seizures, and changes in mental status. Synonyms for meningeal carcinomatosis include leptomeningeal carcinomatosis and neoplastic meningitis. Leptomeningeal carcinomatosis refers to the involvement of both the arachnoid and pia mater, whereas neoplastic meningitis refers to any form of meningitis caused by cancer cells. Other terms that are sometimes used to describe meningeal carcinomatosis include secondary meningitis, metastatic meningitis, and meningeal metastasis.