[Primary bone lymphoma. Retrospective immunohistochemical study of 22 cases]

The clinical, biological, radiological, MRI, and histological features of 22 primary bone lymphomas were reviewed retrospectively.

The standard pathology slides were reexamined with an immunohistochemistry study. Results of two treatments, chemotherapy alone versus chemotherapy then radiotherapy, were compared in terms of local control and patient survival.

Mean age of the patients was 53 years; male gender predominated (M/F=2/1). The most frequent clinical sign was pain and 32% of the patients had a pathological fracture. The long bones were generally involved. The typical radiographic image was a permeable bone defect. MRI demonstrated heterogeneous signals on the T2 images. Technetium scintigraphy (performed in all patients) was very sensitive. Histology generally described diffuse large centroblastic lymphoid cells, all with B phenotype. Twelve patients were treated with chemotherapy alone and eight with chemotherapy and radiotherapy. One patient was only given palliative treatment with corticosteroids due to major immunodepression. The last patient, a 79-year-old woman, developed a tumor of the femoral neck; at surgery section of the neck removed the entire tumor, but radiotherapy (30 Gy) centered on the femur was nevertheless performed. Only patients with fractures were operated. Mean follow-up in this series was 48 months (range 4-120). Mean 5-year Kaplan-Meier survival was 74.41% for the overall series, 83.33% for the chemotherapy group and 82.50% for the chemotherapy-radiotherapy group.

We were unable to demonstrate any significant difference in survival between the two types of treatment. None of the patients experience local relapse. Our observations suggest that technetium scintigraphy is more sensitive than MRI and more specific for diagnosis. Radiography, together with clinical examination and is indicated to monitor these patients during and after treatment. Based on this series, patients with primary bone lymphoma should be given chemotherapy, either alone or combined with radiotherapy, rather than radiotherapy alone. Surgery is not indicated except to obtain a biopsy and to treat mechanical complications.