Pyogenic granuloma stimulates angiogenesis in the chick embryo chorioallantoic membrane.

Ten samples of pyogenic granuloma and 10 of normal skin from age- and sex-matched controls were grafted onto the chick embryo chorioallantoic membrane (CAM) to investigate their possible angiogenic activity. The angiogenic response in pathological and control implants was assessed on histologic sections by a planimetric point-count method 4 days after grafting. The CAM mast cells were also quantified. The vascular counts in the area underlying the pyogenic granuloma were four times higher than those of normal skin. A higher number of mucosa-like mast cells was detected in the intermediate mesenchyme of the CAM in pathological samples in comparison to controls. Pyogenic granuloma may promote angiogenesis leading to release of several angiogenic factors. The role played in angiogenic response by the inflammatory cells, mainly mast cells, forming the perilesional infiltrate was supported by this study.