periosteal chondroma

per·i·os·te·al chon·dro·ma

a chondroma that develops from periosteum or periosteal connective tissue.
References in periodicals archive ?
Histologically, these tumors usually demonstrate definitive anaplasia, although sometimes the distinction between a periosteal chondroma and low-grade chondrosarcoma is difficult or indeterminate.
Periosteal chondroma and periosteal chondrosarcoma.