A 20-year-old male has a lytic expansile lesion at the proximal tibia epiphysis. X-ray shows a soap-bubble appearance with cortical thinning. Histology shows osteoclast-like multinucleated giant cells evenly distributed in a mononuclear stromal background. Which is the MOST accurate characterisation of this lesion?
- A Giant cell-rich osteosarcoma — treat with neo-adjuvant chemotherapy
- B Giant cell tumour of bone (GCT) — locally aggressive, treat with extended intralesional curettage and phenol cauterisation ✓
- C Aneurysmal bone cyst — treat with curettage and bone graft
- D Chondroblastoma — treat with curettage and bone cement
Explanation
Giant cell tumour of bone characteristically occurs in the epiphysis of skeletally mature individuals (closed physis), has a soap-bubble lytic appearance, and histologically shows uniform distribution of osteoclast-like giant cells (>10 nuclei per cell) within mononuclear stromal cells — the stromal cells are the neoplastic population (H3F3A/B mutations). Treatment is extended curettage with high-speed burring, adjuvant cauterisation (phenol, liquid nitrogen, or argon beam), and filling with polymethylmethacrylate cement ± bone graft. Denosumab (anti-RANK-L) is used for unresectable or recurrent cases. Giant cell-rich osteosarcoma has hypercellular pleomorphic stroma.
Reference: Maheshwari Essential Orthopaedics, 6th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.