Central giant cell lesions of the jaws: a clinicopathologic study.

The biologic behavior of central giant cell lesions of the jaws ranges from quiescent to aggressive with destructive expansion. To date, these variations have not been explained by the findings of routine histologic examination. This retrospective clinicopathologic study of giant cell lesions was performed to search for histologic correlates of biologic behavior. Lesions in 17 patients were classified clinically as nonaggressive (group I) or aggressive (group II). In general, group II lesions affected children at an earlier age, were larger at the time of diagnosis, and recurred more frequently. The following histologic parameters were assessed: fractional surface area occupied by giant cells (FSA), relative size index of giant cells (RSI), stromal characteristics, mitotic index, inflammatory cells, and hemosiderin content. Histologic differences between the two groups were not as clear as the differences in biologic behavior. However, aggressive lesions had a higher RSI, and recurrent giant cells lesions had a higher RSI and FSA; these parameters warrant further study. In addition, electron microscopic differences in a small number of aggressive and nonaggressive lesions were documented.