A 30-year-old woman has a lytic expansile lesion in the epiphysis of the distal femur with a soap-bubble appearance on X-ray. She has local pain and swelling. The lesion abuts the articular surface. Biopsy shows spindle cells and multinucleated giant cells. The most likely diagnosis is:
- A Giant cell tumour of bone ✓
- B Aneurysmal bone cyst
- C Simple (unicameral) bone cyst
- D Chondroblastoma
Correct answer: A. Giant cell tumour of bone
Explanation
Giant cell tumour (GCT) of bone is a locally aggressive tumour occurring in young adults after skeletal maturity, characteristically in the epiphysis extending to the subchondral bone of long bones — most commonly around the knee. The soap-bubble lytic appearance extending to the articular surface in a patient with closed physis is classic. Histology shows numerous osteoclast-like multinucleated giant cells on a background of mononuclear stromal cells. Local recurrence after curettage is around 25%.
Reference: Maheshwari Essential Orthopaedics, 6th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.