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

Background: 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.
Patients and Methods: 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.
Results: 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.
Conclusions: 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.