FRCR 2A Question of Day #4 : Musculoskeletal

Question:

A 25-year-old woman presents with progressively worsening knee pain and swelling. An X-ray of the distal femur reveals a lytic, expansile lesion in the epiphyseal region extending to the subchondral bone with a narrow zone of transition and no periosteal reaction. An MRI shows a well-defined lesion with low signal on T1-weighted imaging and high signal on T2-weighted imaging, with cortical thinning but no breach. What is the most likely diagnosis?

1. Osteosarcoma
2. Giant cell tumor of bone
3. Chondroblastoma
4. Aneurysmal bone cyst
5. Fibrous dysplasia

Correct Answer: Giant cell tumor of bone

Explanation:

Giant cell tumor of bone (GCT) is a benign but locally aggressive bone tumor, commonly affecting young adults between the ages of 20 and 40. It typically occurs in the epiphysis