Presentation
4-month history of lower leg swelling and pain.
Patient Data



Lytic lesion involving the cortex of the medial diaphysis, metaphysis, and epiphysis of the distal femur. The remaining medullary bone shows a permeative lytic pattern. The mass has a wide zone of transition. There is a lamellated periosteal reaction with a Codman triangle adjacent to the mass.
Impression of spherical soft tissue component, however, there is no clear osteoid tumour matrix. No joint involvement.
Case Discussion
Histology confirmed this lesion to be a typical osteosarcoma.
Osteosarcoma is the most common malignant bone tumour in childhood. Patients present with non-specific symptoms such as local pain and swelling which may result in a delay in diagnosis. Osteosarcoma has a tendency to be found at sites of high bone turnover 1.
The radiographic appearance of osteosarcoma varies widely and is related to its histological subtype 2. Treatment is dependent on staging, surgical resectability, and response to chemotherapy.