Benign Bone Tumours: NEET PG High-Yield
Orthopedic Oncology: Lesion Localization and Characteristics
1. Key Benign Bone Lesions
| Tumour | Key Clinical/Radiographic Feature |
|---|---|
| Osteoid Osteoma | Nocturnal pain, relieved by Aspirin/NSAIDs. Central radiolucent nidus. |
| Osteochondroma | The most common benign tumour. Cartilage-capped bony projection pointing away from the joint. |
| Giant Cell Tumour (GCT) | Epiphyseal location. “Soap-bubble” appearance. Locally aggressive. |
| Simple Bone Cyst (UBC) | “Fallen leaf sign” (pathological fracture). Metaphyseal location. |
| Aneurysmal Bone Cyst (ABC) | “Fluid-fluid levels” on MRI. Rapidly expanding, lytic lesion. |
2. NEET High-Yield Pearls
- The “Epiphyseal” Rule: Remember GCT (Giant Cell Tumour) and Chondroblastoma as the primary lesions occurring in the epiphysis after skeletal maturity.
- Osteoid Osteoma vs. Osteoblastoma: Both have similar histology, but Osteoid Osteoma is <2 cm (pain responsive to NSAIDs), while Osteoblastoma is >2 cm (pain poorly responsive to NSAIDs).
- Malignant Transformation: Hereditary Multiple Exostosis (HME) has a higher risk of malignant transformation (to chondrosarcoma) compared to solitary osteochondroma.
- GCT Treatment: Intralesional curettage with adjuvant therapy (e.g., phenol, bone cement) is the standard, but it has a high recurrence rate.