Ossifying fibroma of bone. Report of two cases.

Two cases are reported of a hitherto undescribed type of lesion for which the term "ossifying fibroma of bone" is suggested. The lesions occurred in children aged 12 and 13 years, and involved the tibia and the humerus. Histologically they consisted of fibrous tissue containing small, partly calcified spherules: in this respect they differ from the usual types of fibro-osseous lesion such as fibrous dysplasia and osteofibrous dysplasia. The term "ossifying fibroma" is proposed for this condition, although in the past it has been applied to other types of bone lesion.