Metaplastic ossification in a cutaneous pyogenic granuloma: a case report.

Cutaneous ossification may occur in association with a variety of cutaneous neoplasms and inflammatory conditions, such as pilomatricomas, basal cell carcinomas, nevi, chondroid syringomas, venous stasis, and scars. However, it has rarely been reported in pyogenic granuloma, a relatively common benign vascular tumor of the skin and mucous membranes. We herein presented a rare case of cutaneous pyogenic granuloma with ectopic ossification on the big toe of a 37-year-old man, with high recurrence despite repeated CO2 laser ablations. We propose the hypothesis that vascular endothelial growth factor (VEGF) and bone morphogenetic proteins (BMPs) play pathologic roles in the development of ectopic bone formation in pyogenic granuloma.