X-Ray knee joint
Description of Case No. 2:
The slightly expansile lytic lesion is present in the lateral tibial plateau. Overlying cortex appears thin. The lesion is extending up to the articular surface of the knee joint. No surrounding sclerosis is seen. Joint spaces are normal.
Giant cell tumor (GCT)
Key Points of Case No. 2:
Giant cell tumors (GCT’s) are common benign bone tumors also known as osteoclastomas. They arise from metaphysis and extends into the epiphysis of the long bones. The lesions usually shows narrow zone of transition, thin cortex, no sclerosis. Differentials include chondroblastoma, aneurysmal bone cyst and enchondroma.
- Chondroblastomas (Codman tumors) arises from epiphysis. They appear as lucent lesions with the thin sclerotic rim. Internal calcifications can be seen. Joint effusion is seen in one-third of the patients.
- Aneurysmal bone cysts (ABC) are expansile tumor-like lesions. They appear as well-defined expansile osteolytic lesions with thin sclerotic margins.
- Enchondromas are benign medullary cartilaginous neoplasms. These are expansile lytic lesions having endosteal scalloping with “rings and arcs” calcifications. No periosteal reaction.