[Isolated central nervous system relapse of diffuse large B-cell lymphoma in the era of immunochemotherapy]

Diffuse large B-cell lymphoma (DLBCL) is the most common histologic subtype of non-Hodgkin's lymphoma. Standard chemotherapy is CHOP regimen (cyclophosphamide, doxorubicin, vincristine and prednisone). Addition of rituximab to standard chemotherapy regimen significantly increased the success of treatment and overall survival in DLBCL patients. The incidence of isolated relapse of lymphoma in the central nervous system (CNS) occurs in 1.2% to 10.4% of patients, and the outcome is almost always fatal. In this paper, we report the clinical course in a patient with advanced large B-cell lymphoma, who had been treated with immunochemotherapy but developed isolated CNS relapse of lymphoma shortly after achieving complete remission. There is still no consensus regarding the administration of prophylaxis for CNS relapse of lymphoma in patients with DLBCL, hence the question when and how to conduct the prophylaxis remains unresolved. The risk of CNS relapse of lymphoma in young patients with a low risk of death is decreased and it is classified as score 0 and 1 according to the International Prognostic Index (IPI), while the risk is increased in patients with score 2 to 5 according to the same classification. The risk of CNS relapse of lymphoma is increased if the disease is found in the head, neck, bone marrow or testicle. According to the results of some studies, the addition of rituximab to standard chemotherapy as well as intrathecal methotrexate CNS prophylaxis or prophylactic head irradiation do not reduce the risk of relapse of lymphoma in the CNS. Some studies suggest that high-dose intravenous methotrexate may help reduce the risk of CNS relapse in high-risk patients, but it needs to be confirmed in future researches.