label: neoplastic meningitis
label_lc: neoplastic meningitis
description: Metastatic neoplasm in which the tumor cells spread to leptomeninges (pia and arachnoid) and subarachnoid space. The most common primary tumors metastasizing to the leptomeninges are breast and lung carcinomas, melanoma, aggressive non-Hodgkin lymphoma, and acute lymphocytic leukemia.