Primary bone lymphoma is a very uncommon malignancy, which is responsible for 3% of all bone tumors. We report a case of an 80-year-old patient with chronic back pain associated with a pathological T9 fracture. During admission, spinal cord compression with paraparesis was detected and managed with radiotherapy. After investigation, it was discovered to be caused by a primary bone lymphoma. Staging showed multiple bone lesions compatible with polyostotic lymphoma. Histopathology revealed a diffuse large B-cell lymphoma, which was treated with chemotherapy (age-adjusted R-CHOP [rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone] regimen). In this case report, imaging modalities used to diagnose and stage the disease are discussed. Traditional and new prognostic tools and treatment are also reviewed.