Non ossifying fibroma

Clinical:

  • A 10 years old girl
  • Presented with pain over right leg
  • Aggravated by prolong walking and standing
  • No history of trauma or fever
  • Partially relieves with analgesic
  • No constitutional symptoms
  • Clinically a swelling felt at proximal tibia, 2×2 cm, bony hard, non-tender, no overlying skin changes. Range of motion right knee is normal. No neurological deficit.
Plain radiograph of right tibia and fibula in AP and lateral views

Radiographic findings:

  • A lytic lesion at anterior cortex of proximal right tibia
  • It measures about 3.1 x 0.8 cm.
  • Narrow zone of transition
  • Presence of endosteal scalloping
  • No matrix calcification
  • No cortical breach , periosteal reaction or associated soft tissue mass is seen.
  • Knee and ankle joints are intact.

Diagnosis: Non ossifying fibroma of right tibia

Discussion:

  • Non ossifying fibroma is a common focal lesion in the bones.
  • It is estimated to be present in up to 30% of the asymptomatic population in the first and second decade of life
  • Most common between 8-20 years of age
  • They are not neoplasms and, according to WHO, belong to the group of developmental abnormalities
  • On radiograph seen asĀ  lytic lesion, usually oval, surrounded with a thin sclerotic rim, with a long axis parallel to the axis of the bone
  • The lesions are usually found in the metaphyseal areas, mainly in bones constituting the knee joint
  • Geographical, sclerotic rim, endosteal scalloping
  • Migrates toward centre of diaphysis and resolve with age
  • May undergo pathologic fracture, no malignant transformation

Progress of patient:

  • On conservative management with analgesic
  • Repeat radiograph six months after initial presentation shows no interval change of bone lesion
Author: radhianahassan