Known meningeal involvement of multiple myeloma. Exhibits clinical signs of meningeal involvement of MM Meningeal carcinomatosis Any active central nervous system or meningeal involvement Exhibiting clinical signs of meningeal involvement of multiple myeloma History or clinical signs of meningeal or active CNS involvement Clinical signs of or documented leptomeningeal carcinomatosis. Features such as headache, nuchal rigidity, and photophobia may indicate meningeal involvement. Documented history of central nervous system (CNS) involvement or exhibits clinical signs of meningeal involvement of multiple myeloma. If either is suspected, whole body magnetic resonance imaging (MRI) and lumbar cytology are required Known active central nervous system (CNS) involvement or exhibits clinical signs of meningeal involvement of multiple myeloma Subjects must not have known central nervous system involvement by disease (parenchymal, meningeal or cerebrospinal fluid) Active meningeal or central nervous system disease Participants who have known central nervous system, meningeal, or epidural disease including brain metastases. Patients with CNS parenchymal or meningeal-based lesions that are present at study entry evaluation are NOT eligible Presence of diffuse lepto or pachy meningeal carcinomatosis (focal/localized involvement from limited meningeal based metastases acceptable), greater than 1 cm mid-line shift, uncal herniation, or severe hemorrhage/hydrocephalous (small intra-lesional hemorrhage or anticipated surgical cavity is acceptable); patients with seizure at presentation who have been started on levetiracetam and have been stable for 48 hours prior to study registration are eligible at the discretion of treating physician Central nervous system or meningeal involvement Patients with active central nervous system (CNS) disease, defined as brain or meningeal metastases that are not in complete remission Known meningeal involvement of MM. Exhibiting clinical signs of or has a known history of meningeal or central nervous system involvement by multiple myeloma Exhibiting clinical signs of meningeal involvement of multiple myeloma New or progressive brain or meningeal or spinal metastases Subject who has central nervous system (CNS) or meningeal involvement by lymphoma. Participant is exhibiting clinical signs of meningeal involvement of multiple myeloma Presence of meningeal carcinomatosis Meningeal carcinomatosis Patients with known central nervous system, meningeal, or epidural disease. Clinical signs of meningeal involvement of multiple myeloma Patient has active or history of central nervous system (CNS) disease or meningeal involvement Subjects who have new or progressive brain or meningeal or spinal metastases. Brain metastases, meningeal tumours or other metastases in the central nervous system Uncontrolled central nervous system (CNS) metastases, meningeal carcinomatosis, malignant seizures, or a disease that either causes or threatens neurologic compromise (e.g., unstable vertebral metastases). Presence of confirmed distant metastases, including central nervous system and vertebral or meningeal involvement History or clinical evidence of central nervous system (CNS), meningeal, or epidural disease, including brain metastasis. Active central nervous system or meningeal involvement by lymphoma; patients with a history of central nervous system (CNS) or meningeal involvement must be in a documented remission by cerebrospinal fluid (CSF) evaluation and contrast magnetic resonance imaging (MRI) for at least 3 months prior to study entry Meningeal carcinomatosis. Distant metastases, including CNS and vertebral or meningeal involvement Patients with known central nervous system, meningeal, or epidural disease. Patients with stable brain metastases following definitive local treatment are eligible if steroid requirement is <10 mg/day of prednisone (or equivalent). Subjects who have new or progressive brain or meningeal or spinal metastases Known active meningeal infection Uncontrolled meningeal leukemia Meningeal carcinomatosis. Known central nervous system, meningeal or epidural disease including brain metastases Subjects who have new or progressive brain or meningeal or spinal metastases. Diagnosed with meningeal carcinomatosis.