Metastases to the meninges

Abstract Leptomeningeal metastasis, or spread of cancer into the cerebrospinal fluid-filled leptomeningeal compartment and the leptomeninges composed of the pia and the arachnoid, poses diagnostic and therapeutic challenges. Integration of clinical, imaging, and cerebrospinal fluid assessments enables identification of leptomeningeal metastatic subtypes, and supports rational clinical decision-making. Treatment options include intrathecal and systemic pharmacotherapies, as well as radiotherapy. However, outcomes remain poor. New molecular diagnostics and improvements in mechanistic understanding of leptomeningeal metastasis may empower new therapeutic strategies in the near future. Such approaches will be invaluable as more cancer patients survive longer, and are at increased risk of developing leptomeningeal metastasis.