Fibroxanthomas can be divided into:
non-ossifying fibroma (>2 cm)
fibrous cortical defect (<2 cm)
Both are pathologically identical.
Non-ossifying fibromas have the following features (all shown here):
present in adolescents and young adults
commonest location is the femur and tibia
dia-metaphyseal in location
eccentric with mild expansion
well defined lucent lesion with a sclerotic margin
cortical thinning, but not breach
Lesions are asymptomatic and are usually an incidental finding. Lesions often spontaneously regress.
Case courtesy of Dr. Ian Bickle.