Herein, we report a unique case of primary cauda equina diffuse large B-cell lymphoma....Fluorescence in situ hybridization (FISH) analysis from resected tissue was...positive for BCL6 rearrangement in 80% of nuclei.... Our patient was initially treated with R-CHOP with mid-cycle HD-MTX achieving a partial response. Under our care, she was further treated with two cycles of MATRIX resulting in complete remission.