[Configuration and position of centrioles in mono- and multinuclear cells of giant cell tumors of the long bones].

In multinuclear cells of giant cell tumours of long bones studied in biopsies and histiotypic cultures the centrioles were found to be grouped at a distance from the nuclei, forming a giant centrosphere made of diplosomes in equal number to that of the nuclei. This arrangement renders the possibility of new mitotic activity highly unlikely. By contrast, close contacts between multinuclear cells and stromal cells together with the collapse of membranes between cells in contact and the centriolar arrangement represent arguments in favour of genesis by fusion from mononuclear cells of stromal type, in common with many polykaryons. The multinuclear cells of these tumours would appear to represent only the final stage in the evolution of certain mononuclear cells.