A non-ossifying fibroma is a benign (non-cancerous) bone growth that usually occurs in children and adolescents. It is a collection of fibrous tissue that can form in the bone. These growths are generally found in the long bones, like the legs. Most of the time, non-ossifying fibromas don’t cause any problems and often go away on their own as the child grows. They are usually discovered incidentally during X-rays taken for other reasons. Surgical management may be recommended if the lesion is large enough to pose a risk for fracture.

Fibrous dysplasia is a bone condition where normal bone is replaced by fibrous tissue, leading to weakened and sometimes deformed bones. It can affect one bone or multiple bones and often occurs in children and young adults. People with fibrous dysplasia might experience pain, swelling, or fractures, and their bones may look uneven or misshapen on X-rays. Surgical treatment may be recommended if there is persistent pain, deformity, a non-healing fracture, or a fracture through the lesion.

Osteofibrous dysplasia is a rare bone condition where normal bone is replaced by fibrous tissue and immature bone, leading to a thickening and weakening of the affected area. It most commonly occurs in the lower leg, particularly in young children. People with osteofibrous dysplasia might notice swelling or have pain in the affected bone. While it's benign (not cancerous), it can sometimes look like a more serious condition on X-rays. Treatment may include monitoring or surgery if necessary.