Dramatical improvement of chemoresistant bone lymphoma with rituximab.

Non-Hodgkin's lymphoma of the bone is a very rare disease that accounts for approximately 5% of all extranodal non-Hodgkin's lymphomas and for 7-10% of primary bone tumours. We report the case of a 28-year-old man who, in June 2001, presented with a right humerus showing painful destructive lesions with pathological fractures. Biopsy revealed diffuse, large B-cell non-Hodgkin's lymphoma expressing CD20. The patient received six cycles of conventional chemotherapeutic regimen, including cyclophosphamide, doxorubicin, vincristine and prednisone, and VP-16 (etoposide), ifosfamide and mitoxantrone. His arm pain worsened, and x-rays demonstrated progressive disease. He began a trial of rituximab, 750 mg/week, for 4 weeks. There was improvement in pain after the first infusion. Radiographic studies conducted 3 months after rituximab therapy showed marked improvement in his humerus disease. MRI showed a decrease of tumour volume with residual minor signal abnormalities of the bone marrow. He had no evidence of recurrent lymphoma 24 months later.