Non-ossifying fibroma of the right clavicle.

Non-ossifying fibromas (NOFs) or fibroxanthomas are benign intracortical, multilocular and well-circumscribed lesions, which most commonly affect children and adolescents with an estimated prevalence of 30%-40% of all normal children. They are most commonly located in the distal femoral and distal tibial metaphysis although they can also be found in the fibula and upper extremity. Clinically, NOFs are asymptomatic and are detected only incidentally on radiographs where they appear as solitary, eccentric and lytic lesion in the metaphysis of a long bone and often polycyclic in shape. In most cases, no treatment is needed for an NOF other than simple observation due to a high rate of spontaneous regression at skeletal maturity. However, surgical treatment is considered in certain cases when the NOF is large or symptoms are present. We present an unusual case of a large NOF in the right clavicle of a 27-year-old woman who came to us with a 3-year history of a painless swelling on the right side of her upper chest. Radiographic evaluation of her tumour revealed a Ritschl Stage C lesion which was subsequently treated successfully by a near-total cleidectomy without recurrence over a 4-year of the follow-up period. We concluded that open-mindedness remains an important attribute a doctor must possess in order not to miss some rather unlikely diagnosis.