Increased expression of vascular endothelial growth factor in pyogenic granulomas

The expression of vascular endothelial growth factor (VEGF) was analysed in biopsy samples from patients with pyogenic granuloma. The results disclose d the presence of a strong VEGF signal in pyogenic granulomas, which are co nstituted by a vast majority of cells of endothelial lineage. A marked posi tivity was evident in areas of proliferating endothelial cells without vess el lumen formation. In the same respect, staining for VEGF was less marked in the vessels with a well-developed lumen. The fact that VEGF production a ppears to be limited to endothelial cell precursors or immature endothelial cells prior to the complete development of the vessels, leads to the possi bility that VEGF may act as an autocrine factor in circumstances of endothe lial cell stimulation.