Spontaneous regression of exostoses: two case reports.

Exostoses are a common skeletal disorder. Despite their incidence, little is yet known about their origin and biological behaviour. In particular, spontaneous regression of exostoses--an extremely rare event--is still a subject for debate. In this study, we describe two additional cases of spontaneous regression of exostosis; one was a solitary lesion while the other occurred in a patient with multiple heritable exostoses. Radiographic findings are presented along with some of the theories which aim at explaining this phenomenon.