[Multinucleated giant cells in cultured giant cell tumor of bone]

Further observations on multinucleated giant cells (MGCs) in 12 giant cell tumors of bone (GCT) were made, by means of tissue culture, electron microscopy and immunohistochemistry. In continuous in vitro culture, two distinct types of MGCs were found and herein termed preliminarily short-lived MGCs and long-lived MGCs respectively. The former type had limited life span of about 2-3 weeks, whereas the latter type of MGCs maintained growth or continual formation. They had entirely different appearance and characteristics. This fact reflects two types of MGCs exist in GCT in vivo. Besides, the origin of MGCs were also investigated and discussed in considerable depth.