Primary lymphoma of bone

Primary lymphoma of bone (PLB) is a rare clinical-pathological entity representing less than 1% of all lymphomas. This work was aimed to review the presentation characteristics of PLB at the Instituto Nacional de Cancerología including its management and evolution.

Thirty cases of lymphoma of bone were diagnosed between 1972 and 1999 from a database including 577 patients with lymphoma. Among them, only 8 patients (1.36% of the total lymphomas) met the criteria set out to be diagnosed as primary lymphoma of bone, stage IE. In all patients, diagnosis was histopathologically made through open biopsy, and they were classified in accordance with the former criteria of the Working Formulation (WF). This review applied the current criteria of the World Health Organization (WHO).

Three women and five men with a mean age of 40 years (range 20-65) were identified. Mean physical performance (Karnofsky) was 80%. Six patients presented clinically evident disease of the affected region. The most frequent symptom was pain at the site of the lesion in 3 patients, being the cardinal symptom in 1 patient. Histological diagnosis was diffuse large cell lymphoma, and B immunophenotype was confirmed in 5 patients. Five patients received sequential chemotherapy and radiotherapy; 1 patient received chemotherapy; and 2 patients received exclusive radiotherapy. The chemotherapy regimes were based on anthracyclines. Five patients presented complete response and 3 patients showed progressive disease. One patient showing complete response relapse 16 years after the treatment. The mean follow-up in this series was 60 months (range 3-190 months). Tumor localization and functional condition of the patient were the best prognostic factors. Surgery was not therapeutic in any case.

PLB still remains a rare clinical-pathological entity, and represented 1.3% of total lymphomas in this series. Sequential anthracycline-based chemotherapy and radiotherapy are the most important therapeutic choices. Functional condition of patients at diagnosis and tumor localization were the most accurate prognostic factors.