Osteoblastic Lesions: Causes, Types & Understanding Bone Abnormalities

Osteoblastic (sclerotic) lesions reflect increased bone formation. Differential:

• Malignant: Osteoblastic metastases (prostate, breast, carcinoid), osteosarcoma (primary, produces osteoid).
• Benign: Osteoid osteoma (painful, <2 cm, nidus), osteoblastoma (larger, spinal), enostosis (bone island), melorheostosis (flowing hyperostosis).
• Metabolic/Reactive: Paget's disease (mosaic bone), healing fracture, callus, myositis ossificans, hyperparathyroidism (subperiosteal resorption + sclerosis), fluorosis.
• Infectious: Chronic osteomyelitis (involucrum, sequestrum).

Imaging

X-ray: sclerosis. CT: matrix mineralization. MRI: edema, soft tissue. Bone scan: ↑ uptake. PET: metabolic activity.

Management

Depends on etiology: resection (tumors), bisphosphonates (Paget's), antibiotics (osteomyelitis), observation (bone islands). Biopsy if malignant suspected.