Leptomeningeal neoplasia: epidemiology, clinical presentation, CSF analysis and diagnostic imaging.

The incidence of leptomeningeal metastasis over the past several decades has increased among solid tumor patients and decerased in patients with hematologic malignancies. Improvements in systemic therapies are likely responsible for both changes; solid tumor patients are living longer and, threfore, are at higher risk to develop leptomeningeal tumors while patients with hematologic malignancy have benefitted from more aggressive central nervous system prophylaxis. Regardless, both types of patients present with symptoms referrable to multiple levels of the central nervous system and a careful dignostic approach incorporating cerebrospinal fluid studies and appropriate neuroimaging is critical.