fibroxanthoma of bone
Fibroxanthoma of bone is a confusing term that is sometimes used to encompass non-ossifying fibroma and fibrous cortical defect, and at other times synonymously with just non-ossifying fibromas. As non-ossifying fibroma and fibrous cortical defect are histologically the same, and differ only in size (non-ossifying fibroma >2-3 cm) it is safe to not lose too much sleep over this one.
The term metaphyseal fibrous defect is probably a safer collective term for the two entities.
Fibrous cortical defect and non-ossifying fibroma are very common, seen in up to 30-40% of skeletally immature children/adolescents .