Non-Hodgkin's Lymphoma of Bone

Primary intraosseous lymphoma of bone, known in the past as reticulum cell sarcoma, is an uncommon malignancy that accounts for less than 5% of primary malignant bone tumors. Over 20% of patients with lymphoma have secondary bone involvement  Most intraosseous lesions are non-Hodgkin's
lymphoma. Non-Hodgkin's lymphoma of bone is found in the femur and pelvis in patients twenty years of age and older. It may present as local pain or swelling. Primary Hodgkin's lymphoma of bone is exceedingly rare and may occur anywhere in the skeleton. Patients generally feel they are in good health otherwise.
     Lymphoma of bone has a variable picture on plain-xray. A lesion may appear as a vague, mottled lucency. This intraosseous lesion usually has permeative pattern of lysis but may appear blastic or sclerotic. Periosteal reaction and cortical destruction follow. Plain radiographs often underestimate the extent of the lesion. CT scan is useful for disease staging and delineating spinal lesions. MRI is helpful in demonstrating bone marrow and soft tissue involvement. Lymphoma has an increased uptake on bone scan. The radiologic differential includes osteosarcoma, Ewing's sarcoma and osteomyelitis. The possibility of metastatic disease needs to be eliminated.
     On gross examination. primary non-Hodgkin's lymphoma of bone is a gray-white tumor that diffusely infiltrates bone.
     Pathological diagnosis requires clinical suspicion of lymphoma for good tissue handling. It is essential to get tissue without crush artifact or decalcification to preserve cell morphology. Needle biopsy is not adequate. Non-Hodgkin's lymphoma appears most commonly with large cells with irregular
cleaved nuclei and prominent nucleoli surrounded by reticulin fibers. The most common subtype is diffuse histiocytic lymphoma. Hodgkin's lymphoma has a mixed cell population with plasma cells, lymphocytes, histiocytes and eosinophils. Reed-Sternberg cells are large, sharply delineated cells with abundant cytoplasm and a double nucleus that make the diagnosis of Hodgkin's lymphoma. The pathologic differential includes Ewing's sarcoma, chronic osteomyelitis and eosinophilic granuloma.
     Treatment of lymphoma of bone is usually radiation and chemotherapy. Clinical staging studies include chest x-ray, bone scan, CBC, serum chemistries, bone marrow aspirate and biopsy. Surgery is only indicated for pathologic fractures. Lymphoma of bone has the best prognosis of all primary malignant bone tumors.

References
l Malloy, PC et al., Lymphoma of Bone, Muscle, and Skin: CT Findings, AJR 159:805-809, October, 1992.

2Bulloughs, Peter, Orthopaedic Pathologv (third edition), Times Mirror International Publishers Limited, London, 1997.

Desai, S et al., Primary Lymphoma of Bone: A Clinicopathologic Study of 25 Cases Reported Over 10 Years, Journal of Surgical Oncology,46:265-269, 1991.

Huvos, Andrew, Bone Tumors: Diagnosis. Treatment and Prognosis, W.B. Saunders, Co., 1991.

Le vis, SJ et al., Malignant Lymphoma of Bone, Canadian Journal of Surgery, 37(1):4349, February, 1994.

12/18/97