# Giant Cell Tumour of Bone > Giant cell tumour of bone for NEET-PG Orthopaedics covers the epiphyseal lytic lesion, Campanacci grading, denosumab and curettage with adjuvant treatment. - Canonical URL: https://prepelephant.com/topics/neet-pg/orthopaedics/giant-cell-tumour-of-bone - Exam / course: NEET-PG · Subject: Orthopaedics - Publisher: PrepElephant (https://prepelephant.com) — Prepared and reviewed by the PrepElephant Academic Review Team - First published: 2026-10-14 - Last updated: 2026-10-14 - Reference basis: Apley's System of Orthopaedics and Fractures; WHO Classification of Soft Tissue and Bone Tumours - How to cite: "Giant Cell Tumour of Bone", PrepElephant, https://prepelephant.com/topics/neet-pg/orthopaedics/giant-cell-tumour-of-bone ## Direct answer Giant cell tumour of bone is a benign but locally aggressive tumour of the epiphysis of a long bone, seen in young adults once the growth plate has closed. The radiograph shows an eccentric lytic lesion reaching the subchondral bone, usually at the knee, and it is graded by the Campanacci system. Treatment is curettage with adjuvants for most lesions, wide resection for aggressive ones, and denosumab for unresectable disease. ## What you must remember - **Age and site:** usually 20 to 40 years, in the epiphysis of long bones, with the knee the commonest region. - **Radiograph:** an eccentric, lytic, soap-bubble lesion reaching the articular surface, with little or no sclerotic rim. - **Histology:** multinucleated osteoclast-like giant cells in a stroma of mononuclear cells, which look the same as those of brown tumour. - **Campanacci grade:** grade 1 is latent with a sclerotic margin, grade 2 is active with an expanded cortex, and grade 3 breaches the cortex with soft-tissue extension. - **Behaviour:** locally aggressive with a high recurrence rate after curettage, and rare pulmonary metastasis in aggressive or recurrent disease. - **Denosumab:** a RANKL inhibitor that reduces osteoclast-like giant cells, used for unresectable or difficult disease, with hypocalcaemia the key side effect. - **Curettage:** intralesional clearance with a high-speed burr, adjuvants such as phenol or liquid nitrogen, and filling with bone graft or cement. ## Choosing the surgical route for an epiphyseal lesion Once a lytic epiphyseal lesion is confirmed, the surgical choice depends on the Campanacci grade, the extent of cortical breach and the state of the joint surface. The steps below follow the logic most textbooks use. 1. **Confirm the diagnosis:** A biopsy is essential, because brown tumour of hyperparathyroidism and aneurysmal bone cyst can look almost identical. Serum calcium and parathyroid hormone are checked to exclude brown tumour. 2. **Grade the lesion:** The Campanacci grade on radiograph and CT separates curettage candidates from those needing wider resection. Grade 1 and 2 lesions are usually curetted, while grade 3 lesions often need wider resection. 3. **Assess the subchondral bone:** Involvement of the subchondral plate and the joint surface complicates curettage and raises the risk of local recurrence. 4. **Curette with adjuvants:** A high-speed burr clears the lesion, and adjuvants such as phenol or liquid nitrogen reduce residual tumour cells. 5. **Fill the cavity:** Bone graft or cement restores strength to the bone, and cement may be preferred where the defect is large. 6. **Consider denosumab:** Denosumab is used to shrink a tumour that is difficult to resect, or instead of surgery when resection is not possible. Serum calcium is monitored throughout treatment. ## Where the exam tries to catch you Giant cell tumour is an exam favourite for its look-alikes, so the traps mostly come from the differentials. - **Trap:** calling an epiphyseal lytic lesion in a thirty-year-old a simple bone cyst — **Correct:** simple cysts sit in a child's metaphysis, whereas giant cell tumour is a locally aggressive adult epiphyseal tumour. - **Trap:** accepting the giant cell pattern without checking calcium — **Correct:** brown tumour of hyperparathyroidism has the same giant cells, so serum calcium and parathyroid hormone must be measured. - **Trap:** assuming pulmonary nodules in giant cell tumour are carcinoma metastases — **Correct:** lung deposits from giant cell tumour can look histologically benign, and the diagnosis rests on the original tumour. ## Frequently asked questions ### At what age does giant cell tumour of bone usually present? Giant cell tumour of bone usually presents between the ages of twenty and forty, after the growth plate has closed. It is rare in children because its origin lies in the epiphysis of a mature bone. ### Which bones are most often affected by giant cell tumour? Giant cell tumour most often involves the distal femur and proximal tibia, which lie around the knee. The distal radius and proximal humerus are the next commonest sites. ### What is Campanacci grading used for in giant cell tumour? Campanacci grading classifies giant cell tumour of bone by radiographic aggressiveness, from grade 1 latent lesions to grade 3 lesions with cortical breach and soft-tissue extension. The grade helps decide whether curettage or wider resection is planned. ### Why is denosumab used in giant cell tumour of bone? Denosumab is used in giant cell tumour of bone because it blocks RANKL, which is needed for the formation of osteoclast-like giant cells. It helps when the tumour cannot be resected cleanly or when surgery must be delayed. Hypocalcaemia is the key side effect to monitor.