Neurologic complications of systemic lymphoma.

Lymphoma denotes a heterogeneous group of neoplasms derived from lymphoreticular tissues. It can cause neurologic symptoms by infiltrating into the meninges or brain parenchyma. Alternatively, lymphomas may metastasize to bone or infiltrate into the epidural space via intervertebral foramina to cause neurologic dysfunction by compressing adjacent CNS structures. These direct effects can occur at any time during the disease process; most distressingly, meningeal infiltration may be the initial site of relapse after a complete remission. Diffuse and more undifferentiated lymphomas are much more likely to be responsible for producing either meningeal infiltration or intraparenchymal lesions. Direct CNS invasion by lymphoma is associated with significant patient morbidity and short survival despite intensive therapy; whether this manifestation of lymphoma can be prevented by prophylactic CNS treatment remains uncertain. CNS complications may also occur as a result of indirect effects of lymphoma. Therefore, CNS dysfunction may develop as a result of infections that occur secondary to immunosuppression, as a result of antineoplastic therapies, or as a result of true paraneoplastic syndromes. It is important to distinguish between these indirect effects and tumor progression because their recognition permits frequently available appropriate treatment modalities to be administered.