ABSTRACT
INTRODUCTION Leptomeningeal metastasis (LM) is defined as malignant infiltration of the pia mater and arachnoid membrane. In patients with solid tumors, LM is referred to as carcinomatous meningitis. In patients with leukemia or lymphoma, it is termed leukemic or lymphomatous meningitis, respectively. LM is also known as neoplastic meningitis.
