Periosteal chondroma of the proximaltibia mimicking Osgood-Schlatter's disease.

We report a case of a periosteal chondroma of the proximal tibia in an 11-year-old girl, which was initially misdiagnosed as Osgood-Schlatter's disease. The absence of pain and meticulous analysis of the imaging findings on initial and follow-up plain radiographs, ultrasound and MRI allowed to suggest the diagnosis of a periosteal chondroma, which was confirmed after biopsy. Besides the difficulty in the imaging diagnosis of the lesion, determination of the optimal treatment strategy may be challenging as well. Given the localization of this lesion close to the growth plate, decision has to be made whether the lesion will be treated surgically or a waitful watching policy will be implemented in order to prevent interference with the normal growth of the bone.