Central nervous system complications of non-Hodgkin's lymphoma. The potential role for prophylactic therapy

In 38 patients with non-Hodgkin's lymphoma, involvement of the central nervous system (CNS) by malignant lymphoma developed during an eight year period. All patients had lymphomatous meningitis; clinical involvement of the spinal nerves or cranial nerves suggested the diagnosis. Spinal fluid was abnormal in 97 per cent of the patients although a positive cytology could be documented in only 67 per cent by lumbar puncture. The histology in 82 per cent of the patients was diffuse. Involvement of the CNS in nodular lymphoma was uncommon (3 per cent), and the histology in virtually all of these patients had converted to diffuse. At the time of diagnosis of CNS disease, 95 per cent of the patients had other evidence of advanced disease; 66 per cent had bone marrow involvement. In only 18 per cent of the patients did CNS disease develop while they were in clinical remission. Eighty-five per cent of the patients treated with whole brain irradiation and intrathecal chemotherapy had a good clinical response. Knowledge of these risk factors permits definition of a group of patients who may benefit from CNS prophylaxis.