Periosteal chondroma: a radiographic spectrum.

The radiographic features of 22 cases of histologically proven periosteal chondroma are analyzed in detail. The typical tumor consisted in an area of outer cortex remodeling (scalloping) involving the metaphyseal lesion of a long bone with slightly overhanging edges and a small amount of cartilage calcified matrix adjacent to the scalloping. The presence of a visible soft tissue mass was uncommon, present in only third of the cases. The radiographic differential diagnosis is analyzed in detail and illustrated.