Bone tumors
Bone tumors range from benign lesions such as osteochondroma and osteoid osteoma to aggressive primary malignancies such as osteosarcoma, chondrosarcoma, and Ewing sarcoma. The diagnostic approach is a radiograph first to characterize the lesion as benign or aggressive, then MRI for local extent, then image-guided biopsy as the confirmatory step, with management ranging from observation to resection and chemotherapy.
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What this article covers
- Overview
A spectrum from benign to aggressively malignant: primary bone tumors range from benign lesions needing no more than observation or NSAIDs (osteochondroma, osteoid osteoma) to a locally aggressive…
- Epidemiology
Osteochondroma is the most common benign bone tumor, in males younger than 25, most often around the knee.
- Risk factors
Hereditary multiple exostoses: EXT1 or EXT2 gene mutation predisposes to multiple osteochondromas, which rarely transform to chondrosarcoma.
- Pathophysiology
Benign cartilage-capped lesions arise from growth-plate cartilage: osteochondroma is a lateral bony projection of the growth plate, continuous with the marrow space and covered by a cartilaginous cap, that points away from the joint.
- Clinical features
Pain character is the first branch point: bone pain worse at night, relieved by NSAIDs, in a small (under 1.5 cm) cortical lesion with a radiolucent core is the hallmark of osteoid osteoma…
- Differential diagnosis
Metastatic bone disease: more common than any primary bone tumor in an adult, especially over 40; lytic metastases most often arise from lung, kidney, thyroid, or breast primaries and blastic…
- Diagnosis
Tissue diagnosis by image-guided or open biopsy confirms the specific tumor type and is the basis every treatment decision rests on; no bone tumor is definitively typed by imaging alone, and biopsy…
- Management
First, stratify by radiographic behavior before deciding on intervention: an asymptomatic, radiographically benign lesion (for example an incidentally found osteochondroma) is managed with…
- Complications
Pathologic fracture through a weakened lesion, a described presentation of osteosarcoma and a risk with any expansile or destructive lesion.
- Prognosis
Primary osteosarcoma usually responds to chemotherapy plus surgery together, while secondary osteosarcoma (from Paget disease, prior radiation, or a bone infarct) carries a poor prognosis.
- Prevention
Genetic counseling and periodic surveillance for hereditary multiple exostoses (EXT1/EXT2 mutation): monitor at-risk relatives for multiple osteochondromas and any growth or pain change suggesting chondrosarcomatous transformation.
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Related articles
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Osteosarcoma is a malignant osteoid-producing bone tumor with a bimodal age distribution, most often arising in the metaphysis around the knee in adolescents and young adults. Diagnosis rests on radiograph findings of Codman triangle or sunburst periosteal reaction confirmed by biopsy, and treatment sequences neoadjuvant chemotherapy, limb-sparing wide resection, and adjuvant chemotherapy.
- Ewing sarcoma
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