Positive Expression of Macrophage Inflammatory Protein-1α and -1β in a Patient with Diffuse Large B-cell Lymphoma Accompanied by Hypercalcemia and Multiple Osteolysis

Multiple osteolysis and hypercalcemia are rare conditions accompanying diffuse large B-cell lymphoma (DLBCL). There have been no reports demonstrating the protein expression of osteoclast-activating factors in such cases. Herein, we report a case of a 38-year-old man with DLBCL, who initially presented with hypercalcemia, multiple osteolysis and renal insufficiency that mimicked multiple myeloma with poor outcome. Immunohistochemical analysis was conducted to examine the expression of macrophage inflammatory protein (MIP)-1α, MIP-1β and receptor activator of NF-kappa B ligand (RANKL) in a lymph node that was obtained at diagnosis. Compared with a control DLBCL sample, we observed increased expression of MIP-1α in lymphoma and vascular endothelial cells and MIP-1β in stromal cells in our case. RANKL expression was not observed in either our case or control cases. MIP is likely associated with the development of osteolysis and hypercalcemia in some lymphoma cases.