Non-Ossifying Fibroma

NOF/Fibrous Cortical Defect/Metaphyseal Fibrous Defects


  • at metaphysis of long bones:- Distal Femur(40%), Tibia(40%), Fibula(10%), Others(10%)
  • the most common benign bone tumor in children and adolescents(age 2-28)
  • Usually an accidental finding; most of the pt. asymptomatic
  • Few present with pathological fracture following trivial trauma


  • well defined, lobulated lesion, eccentric location in metaphyseal area
  • Multilocular appearance/ridges in the bony wall, sclerotic sclloped borders, erosion of cortex
  • No periosteal reaction if no pathlogical fracture.


-: Histological Features:-

 In the defect-

  • Spindle shaped cells in whorled/storiform pattern
  • fibroblast proliferation
  • Giant cells & Foam cells


  • Most are asymptomatic    regress spontaneously with age
  • Most pathological fractures: only need conservative treatment
  • Large symptomatic lesion & lesions > 50% of the bone diameter→   >increased risk of pathological fracture→Curettage & Bone-grafting