Central nervous system involvement in haematological malignancies.

We have reviewed our experience of central nervous system (CNS) involvement in 540 patients with lymphoma or acute leukaemia treated at the Royal Infirmary of Edinburgh between 1979 and 1987. CNS invasion is a significant problem in acute lymphoblastic leukaemia but may well respond to treatment, while in acute non-lymphoblastic leukaemia this complication occurs too infrequently to justify routine CNS prophylaxis. CNS involvement in Hodgkin's disease or non-Hodgkin's lymphoma (NHL) of low-grade malignancy was uncommon, exclusively of the extradural variety, and did not appear to alter the ultimate prognosis. Diffuse leptomeningeal involvement occurred with significant frequency in more aggressive NHL, often while the disease was in systemic remission or during remission induction. The prognosis for leptomeningeal disease or intracranial mass lesions was extremely poor and some form of CNS prophylaxis may be justified in aggressive NHL.