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.