Central nervous system involvement in non-Hodgkin's lymphoma

Fifty-eight Hong Kong Chinese patients with CNS lymphoma were reviewed (primary seven, secondary 51). The incidence of secondary CNS lymphoma in patients with non-Hodgkin's lymphoma was estimated to be 9.4%. The Working Formulation separated subtypes which had a special propensity to involve the CNS. Significant proportions of our patients with secondary CNS lymphoma had other features which were known to be associated with a high risk of CNS disease including stage IV (48/51, 91.4%), bone marrow (26/51, 50.9%), peripheral blood (7.51, 13.7%), nasal (7/51, 13.7%), orbital (3/51, 5.9%), testicular (2/51, 3.9%) and bulky retroperitoneal (6/51, 11.8%) disease. 82% of patients with secondary CNS lymphoma had concurrent systemic disease and a further 12% had systemic relapse shortly afterward. CNS lymphoma is associated with poor prognosis and only 29% and 14% of the patients with primary and secondary CNS lymphoma respectively survived beyond 1 year. Patients responding to therapy had significantly better survival. 69.9% of the deaths were related to progressive systemic disease.