Hematological malignancies and the bone (myeloma excluded)

Bone involvement is a rare event in lymphomas, except in patients with adul t T-cell leukemia/lymphoma associated with HTLVI. It is usually characteris ed by lytic bone lesions located in the metaphysis of long bones or in the axial skeleton. The occurrence of bone lesions reflects a progression of th e disease affecting the prognosis that is related to lymphoma histologic fe atures and staging. Bone lesions may occur in some lymphoproliferative diso rders such as LLC or Waldenstrom's disease, or in myeloproliferative disord ers. They may reflect a progression to a more aggressive disorder with a wo rse prognosis. The treatment of hematologic malignancies presenting with bo ne lesions and/or hypercalcemia is similar to the treatment of the systemic disease. In primary lymphomas of bone presenting with an isolated bone les ion, local treatment with radiation therapy and/or surgical ablation is req uired, and adjuvant chemotherapy may improve the prognosis of these located lymphomas. Glucocorticoid therapy and bisphosphonates are effective in tre ating associated hypercalcemia. Except for myeloma and ATL, the underlying mechanisms responsible for bone involvement in hematologic malignancies rem ain poorly understood. The unusual occurrence of bone lesions in these dise ases probably implies distinct pathogenic mechanisms, but one can speculate that an increased expression of RANK/RANKL, the common final pathway in bo ne resorption, may be involved. Joint Bone Spine 2000; 67 :264-71. (C) 2000 Editions scientifiques et medicales Elsevier SAS.