Primary lymphoma of bone originating in a rib.

Malignant lymphoma originating in the bone is rare and is now recognized as being an independent clinicopathologic entity known as primary lymphoma of bone. A 60-year-old man complaining of right chest and back pain consulted our hospital for further examination. Chest X-ray and computed tomogram revealed osteolysis and a surrounding soft tissue mass in the sixth right rib. An ultrasonically-guided needle biopsy of the tumor was performed, and histologic examination indicated the dense proliferation of similar-sized atypical cells with nucleoli and an irregular nuclear border. A diagnosis of diffuse, medium-sized non-Hodgkin's lymphoma, B-cell type was made. En block resection of the tumor and chest wall was performed. Macroscopically, the tumor measured 7.5 x 4.8 x 3.0 cm in diameter, and the histologic findings were similar to those of the preoperative needle biopsy. Unfortunately, postoperative treatment with radiation therapy and chemotherapy was ultimately unsuccessful, and a local recurrence and metastatic lesions appeared in the stomach and para-aortic abdominal lymph nodes 7 months after the first symptom appeared. The patient died 3 months later. Surgery was chosen as the initial therapy as it was considered that a rib resection would not result in serious respiratory compromise and the complete resection of the tumor would be superior to radiation therapy for local control. Some authors have reported that the surgical resection of a primary lymphoma of the bone originating in a rib can yield a good prognosis. However, it is a systemic disease and a more effective therapeutic strategy should be developed.