GIANT-CELL TUMOR OF BONE - AN IMMUNOHISTOCHEMICAL COMPARATIVE-STUDY

Forty-seven cases of giant cell tumor (GCT) of bone were reviewed path ologically to elucidate the origin of spindle-shaped stromal cells or the histogenesis of mononuclear histiocytic stromal cells and osteocla st-like giant cells (OCGC), To clarify the histogenesis of OCGC, eight cases of sarcoma associated with OCGC were reviewed for a comparative study. Spindle-shaped stromal cells sometimes produced minute foci of osteoid matrix. Proliferating cell nuclear antigen (PCNA) was observe d in spindle-shaped stromal cells and mononuclear histiocytic stromal cells, but not in OCGC, Matrix metalloproteinase (MMP)-9 was expressed by mononuclear histiocytic stromal cells and OCGC, and its expression was correlated with the lung metastasis rate, In both GCT and sarcoma s with OCGC, mononuclear histiocytic stromal cells and OCGC expressed CD68, parathyroid hormone-like protein (PTH-LP), MMP-1 and MMP-9, Immu noreactivity of mononuclear histiocytic stromal cells and OCGC to CD68 , PTH-LP, MMP-1 and MMP-9 was similar between GCT and sarcomas with OC GC, These observations may suggest that mononuclear histiocytic stroma l cells and OCGC are reactively induced with several cytokines acting in an autocrine or paracrine fashion and that these cells are closely related with the biologic aggressiveness of GCT.