[Neurological presentation of non-Hodgkin lymphoma: a diagnostic problem].

In two patients, men aged 69 and 38 years, neurological signs were the first presenting symptoms of systemic non-Hodgkin's lymphoma (NHL). This presentation is uncommon. The patients had focal neurological deficit and elevated serum lactate dehydrogenase (LDH) activity. Neurological manifestations of NHL may be caused by extradural lymphoma or by diffuse leptomeningeal metastasis (meningitis lymphomatosa). A third patient, a woman of 48, had a third form of nervous system involvement, primary cerebral NHL, which is not a metastatic sequel to systemic NHL. Primary neurological presentation of NHL may be difficult to diagnose, particularly in case of prior treatment with corticosteroids.