Non-Ossifying Fibroma (Fibroxanthoma)

non-ossifying fibroma

This 14 year-old boy had radiographs of the ankle performed following a sporting injury. An incidental finding is shown.

Fibroxanthoma can be divided into:

1) Non-ossifying fibroma (> 2cm)

2) Fibrous cortical defect (< 2cm) Both are pathologically identical. Non-ossifying fibromas have the following features (all shown here): 1. Present in adolescents and young adults 2. Commonest location is the femur and tibia 3. Dia-metaphyseal in location 4. Eccentric with mild expansion 5. Well defined lucent lesion with a sclerotic margin 6. Cortical thinning, but not breach. Lesions are asymptomatic and are usually an incidental finding. Lesions often spontaneously regress. Reference: Paediatrics, Donnelly, 6, p90-1.

Credit: Dr Ian Bickle