Clinical features and treatment outcomes of isolated secondary central nervous system lymphomas in Miyazaki Prefecture

Secondary central nervous system lymphoma (SCNSL) without extra-central nervous system (CNS) involvement is characterized by isolated secondary CNS relapse in malignant lymphoma patients. SCNSL is a rare disease, and no standard treatment has yet been established.To elucidate the clinical characteristics and outcomes of SCNSL, we retrospectively analyzed 12 patients (median age 67 years) in Miyazaki prefecture for the last 5 years.The initial histological diagnoses of the patients were diffuse large B-cell lymphoma (DLBCL), mantle-cell lymphoma, and adult T-cell lymphoma in 9, 2, and 1 patient, respectively. We focused on analysis of the 9 SCNSL cases originating from DLBCL. The locations of CNS relapse were the cerebral hemisphere, basal ganglia, and cerebellum in 7, 1, and 1 patient, respectively. Three patients were treated with high-dose methotrexate (HD-MTX) therapy; 4 with whole-brain radiation therapy (WBRTX); and 1 with both HD-MTX and WBRTX. The remaining patients were treated with rituximab. Partial remission was achieved in 6 out of 9 patients (67%); the other 3 patients (33%) did not respond to therapy. Median survival of the 9 patients with CNS relapse was 253 days; 6 of the 9 patients survived for more than 6 months. As of March 2011, 2 HD-MTX group patients but none of the WBRTX group patients were alive.In this retrospective study, 6 of 9 patients with SCNSL originating from DLBCL survived for more than 6 months. Both HD-MTX and WBRTX had clinical benefits in the treatment of SCNSL.