Cancer complications in patients with hematologic malignancies

This chapter reviews the spectrum of neurologic complications associated with lymphoma and leukemia through six representative cases. Malignant cells of both B-cell and T-cell origin have a predilection for infiltrating into the cerebrospinal fluid (CSF) and the meningeal membranes surrounding the brain and the spinal cord. Central nervous system (CNS) involvement can occur at presentation, with systemic progression, and at relapse. In patients with lymphoma, leptomeningeal, intraparenchymal, intramedullary, and epidural involvement may occur. Unique syndromes include lymphomatosis cerebri and neurolymphomatosis. Neurological complications are more frequent with non-Hodgkin lymphoma (NHL) than with Hodgkin lymphoma (HL). CNS involvement by leukemia includes leptomeningeal or intracranial metastases and extramedullary myeloid tumors. Intracranial hemorrhage is also a common complication of leukemia. The incidence of CNS involvement is highest in aggressive lymphomas such as Burkitt lymphoma and acute lymphoblastic leukemia (ALL), ranging from 30% to 50%, and CNS prophylaxis is routinely used in the treatment protocols. In patients with diffuse large B-cell lymphoma (DLBCL), the overall CNS relapse risk is 2-5%, and CNS prophylaxis is reserved for high-risk patients. Neurological involvement with acute myelogenous leukemia (AML) is rare, less than 5%, and even rarer in chronic lymphocytic leukemia (CLL), occurring in less than 1% of patients. CNS involvement can be difficult to diagnose. The clinical presentation varies widely depending on the site of involvement. Brain and spine MRI, CSF analysis with cytology, and flow cytometry may assist in diagnosis. Rarely, NHL and HL may be associated with paraneoplastic syndromes. Limbic encephalitis, paraneoplastic cerebellar degeneration, and granulomatous angiitis of the CNS are the typical paraneoplastic syndromes associated with HL.