A 17-year-old boy with osteosarcoma of the distal femur completes neoadjuvant chemotherapy. Staging CT chest is performed before definitive surgery. The single most common site of haematogenous metastasis in osteosarcoma is:
- A Liver
- B Bone marrow
- C Lung ✓
- D Brain
Correct answer: C. Lung
Explanation
Osteosarcoma spreads haematogenously and the lung is by far the most common site of metastasis, present in about 15 to 20 percent of patients at diagnosis and accounting for the majority of relapses. Pulmonary metastasectomy is offered for resectable disease. Bone is the second most common site, while liver and brain involvement is uncommon at presentation. This is why chest CT is mandatory in the staging workup before planning limb salvage surgery.
Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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