Fibrous cortical defect and non-ossifying fibroma.

THE FIBROUS cortical defect and the non-ossifying fibroma are benign fibrous tumours occurring, in the cortex of the metaphysis, in the long bones of children and young adolescents. The fibrous cortical defect occurs in children usually under ten years of age; occasionally it develops into the more extensive lesion found in young adolescents and known as a non-ossifying fibroma. Despite the superficial dissimilarities the one most probably gives rise to the other. Because of their clinical rarity these tumours still cause misgivings in the minds of pediatricians, orthopaedic surgeons and pathologists. Their real incidence is probably many times greater than their clinical frequency would suggest since most of them are only discovered accidentally, when the patient is X-rayed for some trauma or other to the affected area, or, as we have seen, even in a control X-ray. Unless there is a pathologic fracture through the tumour it is unlikely that there will be any symptoms. In this presentation we review seven cases referred to us.