Bone Lesions on CT Scan: Differential Diagnosis and Next Steps

Focal bone lesions on CT can represent diverse pathologies:

Entity	Typical CT Appearance	Key Features
Bone tumors (benign)	Well‑defined, sclerotic/lucent	Osteoma, enchondroma; often incidental
Bone tumors (malignant)	Aggressive: permeative, cortical destruction, soft‑tissue mass	Osteosarcoma, chondrosarcoma, metastasis
Fractures	Acute: lucent line, edema; Chronic: sclerosis, callus	Correlate with trauma history
Osteomyelitis	Permeative destruction, periosteal reaction, sequestrum	Fever, elevated inflammatory markers
Avascular necrosis	Subchondral collapse, crescent sign, sclerosis	Hip, knee, shoulder; risk factors: steroids, alcohol, trauma
Paget's disease	Cotton‑wool skull, thickened trabeculae, bowing	Pelvis, spine, femur, skull; elevated alkaline phosphatase

Next Steps

• Clinical correlation (pain, labs, history).
• Advanced imaging (MRI for marrow/soft tissue).
• Biopsy if malignancy suspected.