Non-ossifying fibroma (NOF)


Fibroxanthomas can be divided into:

  1. Non-ossifying fibroma (>2 cm)
  2. Fibrous cortical defect (<2 cm)

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.

Case courtesy of Dr Ian Bickle