We are reporting on the cases of twenty patients with periosteal
chondroma to stress the importance of a proper clinical and radiographic
diagnosis of this lesion. Awareness of the features of the lesion helps to
prevent overtreatment of this benign condition, because the cytological
findings may be ominous. Even the radiographic pattern may be suggestive of
malignant disease. Periosteal chondromas apparently arise from under the
periosteum of the diaphysis or metaphysis in adolescents and young adults.
Close cooperation between the surgeon, the radiologist, and the pathologist
is necessary to achieve proper diagnosis and treatment. Marginal excision
is usually effective treatment.