Abstract
Follicular lymphoma is the most common indolent non- Hodgkin lymphoma (NHL) and accounts for approximately 20-30% of all NHL cases in Western countries. In general, systemic therapies are not considered to be curative. Despite this, prognosis is excellent with a 5-year relative survival rate of 90% and median overall survival rates ranging from 10-20 years across numerous studies. The exact incidence of central nervous system (CNS) involvement in cases of follicular lymphoma is unknown, however retrospective data suggest an incidence of 0.2% though this likely represents an underestimation of the true incidence. The optimum treatment approach for CNS disease in follicular lymphoma is poorly defined and no randomized studies exist which prove the superiority of one approach over another. Retrospective data suggest that resection, with or without adjuvant radiation, is an effective strategy for patients with local disease limited to the CNS. In cases where synchronous systemic disease is present, treatment regimens incorporating high-dose methotrexate and bendamustine or anthracycline-based chemotherapy have demonstrated efficacy. We report a case of a 59-year-old female with stage IV follicular lymphoma with synchronous systemic and leptomeningeal involvement who achieved complete remission following treatment with bendamustine, rituximab, and intra-thecal
methotrexate. More long-term follow up data are needed to better characterize the prognosis for patients with CNS involvement who obtain complete remission following initial therapies. Treatment selection for patients with CNS involvement should take into account the presence or absence of systemic disease, patient comorbidities and performance status, and the likelihood of transformation to a high-grade process.