Epidemiology and Clinical features
Mnemonic: LMNOP
Lower extremity predilection (proximal femur > tibial diaphysis)
Male predilection (2:1 to 3:1)
Night pain relieved by NSAIDs (absent in osteoblastoma)
Osteogenic benign tumor
Prostaglandins (PGE2) and Cyclooxygenase (COX1 and 2) release by nidus (explains night pain and response to NSAIDs)
3 Concentric layers
Mnemonic: 3 R
- Radiolucent nidus in center (<1.5 cm) – centrally
- Meshwork of dilated vessels, osteoblasts, osteoid and wove bone
- Bull’s eye appearance on CT if center is calcified
- Double density sign on Bone scan (hot uptake in nidus and cold uptake in reactive zone)
- Size is >2 cm in osteoblastoma
- Rim of fibrovascular tissue – middle
- Absent in osteoblastoma and osteosarcoma
- Reactive bone sclerosis – peripherally
Management
Mnemonic: MRSA
- MRgFUS (MR guided focused Ultrasound) ablation (new non-invasive and radiation free technique)
- Radiofrequency ablation (CT guided core biopsy followed by insertion of radiofrequency electrode through the cannula of biopsy needle and temperature of tip is increased to 90 degree celsius for 6 minutes)
- Not indicated for vertebral lesions (risk of spinal cord injury)
- Not indicated for small bones of hand and feet (risk of skin injury)
- Surgery (Curretage or En-bloc resection of nidus)
- Anti-inflammatory (Spontaneous healing of lesion may be attained in 3-4 years)