Presentation
Three-month history of knee pain and limp.
Patient Data
Ill defined lesion affecting proximal tibial diaphysis and metaphysis. Physis and epiphysis grossly normal. Central areas of lucency and peripheral sclerosis with a wide zone of transition. Aggressive periosteal reaction and Codman's triangle present.
Abnormal signal within proximal tibia, extending across physis into epiphysis but sparing articular surface. Extra-osseous soft tissue component. No other lesion within the imaged bone including joints above and below.
Multiple bilateral pulmonary nodules, up to 3 cm, in keeping with pulmonary metastases.
Abnormal uptake in right ilium, left calvarium and lumbar vertebrae. Findings in keeping with bone metastases. Abnormal uptake in distal left ankle is more likely related to abnormal biomechanical forces given absence of abnormality on MRI.
Case Discussion
This is a case of biopsy proven osteosarcoma, following a relatively typical presentation. As the findings on plain film are typical of an aggressive lesion, it is important to recommend prompt discussion with oncology and referral for staging investigations.