Soap - bubble appearance is seen in:
Ans: A (Giant cell tumour) Ref: Apleys System of orthopaedics and fractures, 9th edition. TumoursExplanation:Giant Cell TumourThe X-rays show a radiolucent area situated eccentrically at the end of a long bone and bounded by the subchondral bone plate.The endosteal margin may be quite obvious, but in aggressive lesions it is ill-defined.The centre sometimes has a soap-bubble appearance due to ridging of the surrounding bone.The cortex is thin and sometimes ballooned: aggressive lesions extend into the soft tissue.The appearance of a 'cystic' lesion in mature bone, extending right up to the subchondral plate, is so characteristic that the diagnosis is seldom in doubt.Ewing's SarcomaThe X-rays usually show an area of bone destruction which, unlike that in osteosarcoma, is predominantly in the mid-diaphysis.New- bone formation may extend along the shaft and sometimes it appears as fusiform layers of bone around the lesion - the so-called 'onion - peel' effect.Often the tumour extends into the surrounding soft tissues, with radiating streaks of ossification and reactive periosteal bone at the proximal and distal margins.These features (the 'sunray' appearance and Codman's triangles) are usually associated w ith osteosarcoma, but they are just as common in Ewing's sarcoma.AdamantinomaIt has a predilection for the anterior cortex of the tibia.The X-ray shows a typical bubble-like defect in the anterior tibial cortex: sometimes there is thickening of the surrounding bone.OsteosarcomaThe X-ray appearances are variableHazy osteolytic areas may alternate with unusually dense osteoblastic areas.The endosteal margin is poorly defined.Often the cortex is breached and the tumour extends into the adjacent tissues; when this happens, streaks of new bone appear, radiating outwards from the cortex - the so-called 'sunburst' effect,Where the tumour emerges from the cortex, reactive new bone forms at the angles of periosteal elevation (Codman's triangle).While both the sunburst appearance and Codman's triangle are typical of osteosarcoma, they may occasionally be seen in other rapidly growing tumours.
Giant cell tumour
Ewing's sarcoma
Adamantinoma
Osteosarcoma
Giant Cell Tumor (GCT) or Osteoclastoma