Giant cell granuloma of the jawbones--a proliferative vascular lesion? Immunohistochemical study with vascular...

To estimate the angiogenic activity in central giant cell granuloma (CGCG) by immunohistochemical stains for vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF). VEGF and bFGF immunoreactivity of the lesional mononuclear (MC) and giant (GC) cells was also investigated.

The study consisted of 41 cases of CGCG. Vascularity was quantified by microvascular volume (MVV) as determined by point counting. In five cases of CGCG, regions at the surrounding border, which demonstrated reactive vascular-rich inflammatory areas, served as control. Immunoreactivity of the MC and GC was assessed as the percentage of VEGF- and bFGF-positive cells from the total number of the respective cell type.

Within CGCG lesions the extent of angiogenesis was low; MVV did not exceed 5% for either VEGF (88% of lesions) or bFGF (78% of lesions). The mean MVV of VEGF- and bFGF-positive blood vessels was 2.9% +/- 2.4% and 3.46% +/- 2.35%, respectively, significantly lower than in the control areas (27.5% +/- 7.3% and 28.08% +/- 5.5%, respectively) (P = 0.043). VEGF-positive and bFGF-positive MC and GC were found in nearly all lesions and in less than half of the lesions, respectively.

The low mean MVV of VEGF- and bFGF-positive blood vessels implies low angiogenic activity, which does not support the designation of CGCG as a true proliferative vascular lesion. MC and GC immunoreactivity for the angiogenic factors is assumed to play an important role in the osteoclastogenesis process, thus contributing to additional growth of the CGCG lesions.