Mast cells play an essential role during development of inflammation after chemical and immunological stimulus, and have been implicated in tissue fibrosis and angiogenesis. Hemangiomas are the most common tumors in the childhood. Pyogenic granulomas are the reactive vaculary lesions that occurs after minor trauma or infection of the skin.

In this study, in sections with stained Toluidine Blue, mast cells were counted 11 longstanding capillary hemangiomas of childhood and 10 pyogenic granulomas of recent onset in an attempt to understand the role of the mast cells in the proliferation or maturation of the blood vessel. The average number of mast cells in five high power field (x400 magnification) was 7.72±5.33 (mean±SE) in the capillary hemangiomas and 6.49±4.57 (mean±SE) in the pyogenic granulomas. There was no difference between capillary hemangiomas and pyogenic granulomas in the average number of mast cells (p= 0.62, p>0.05). These results suggest that mast cells may not play an essential, early role in the proliferation of blood vessels in pyogenic granulomas, but may be related to involution and maturation of blood vessels in capillary hemangiomas.