Which is the most common primary malignant bone tumor?

Which is the most common primary malignant bone tumor?

• A. Ewing Sarcoma
• B. Osteosarcoma
• C. Chondrosarcoma
• D. Osteomyelitis

Answer: (B)

Osteosarcoma is the most common primary malignant bone tumor, especially in adolescents during their growth spurts. It arises from malignant osteoblasts that produce osteoid and most often involves the metaphyses of long bones, such as the distal femur or proximal tibia. Clinically, patients typically have deep bone pain and swelling; radiographs show an aggressive lesion with periosteal reaction, classically a sunburst pattern with Codman triangle. Labs may show elevated alkaline phosphatase reflecting increased osteoblastic activity, and biopsy confirms malignant osteoid-producing cells. Early lung metastases are common if not treated promptly, and management relies on chemotherapy plus wide surgical resection, often limb-sparing. Ewing sarcoma also occurs in young patients but is less common overall and tends to arise in the diaphysis with onion-skin periosteal reaction; chondrosarcoma occurs in older adults and produces cartilaginous matrix; osteomyelitis is infection, not a malignant tumor.

Osteosarcoma is the most common primary malignant bone tumor, especially in adolescents during their growth spurts. It arises from malignant osteoblasts that produce osteoid and most often involves the metaphyses of long bones, such as the distal femur or proximal tibia. Clinically, patients typically have deep bone pain and swelling; radiographs show an aggressive lesion with periosteal reaction, classically a sunburst pattern with Codman triangle. Labs may show elevated alkaline phosphatase reflecting increased osteoblastic activity, and biopsy confirms malignant osteoid-producing cells. Early lung metastases are common if not treated promptly, and management relies on chemotherapy plus wide surgical resection, often limb-sparing. Ewing sarcoma also occurs in young patients but is less common overall and tends to arise in the diaphysis with onion-skin periosteal reaction; chondrosarcoma occurs in older adults and produces cartilaginous matrix; osteomyelitis is infection, not a malignant tumor.