Bone Tumors

Abstract

Diaphysis = shaft; epiphysis = growth plate and end of bone; metaphysis = conical portion between diaphysis and epiphysis. Prevalence: Osteosarcoma > chondrosarcoma > Ewing’s > malignant fibrous histiocytoma (MFH). Sixty percent cases occur between 10 and 20 years of age (most active age of skeletal growth). Eighty percent cases in long bones until epiphyseal closure (then ∼occur with appendicular skeleton). In patients >60 years, >50% cases arise from other conditions (i.e., Paget’s disease, fibrous dysplasia) → poor chemo response. Osteosarcoma: Malignant osteoid is hallmark (not seen in chondro­sarcoma). Most common bone tumor in children. Seventy-five percent present in metaphyses of long bones with local pain/swelling. Eighty-five percent are grades 3–4. Osteosarcoma arising as second malignancy s/p chemo or RT does not necessarily have worse prognosis, but controversial. Associated with Li-Fraumeni Syndrome (p53) and retinoblastoma. Periosteal (juxtacortical) osteosarcomas are usually low-grade, localized with rare DM. Most present in popliteal fossa. Eighty to ninety percent curable with surgery alone. Osteosarcoma: Most common in femur > tibia > humerus. DM most common in lung > bone/BM. Chondrosarcoma: ∼25% of all primary bone cancers. Most common in the femur. Frequent local recurrence, DM less common than osteosarcoma. 1/3 are high-grade. MFH: Very aggressive locally with frequent DM. Often presents with fracture. Fibrosarcoma: High-grade, behaves like osteosarcoma. Commonly presents with fractures. Chordoma: Physaliferous cell (“bubbly cell”) is hallmark. Most often in sacrococcygeal area, base of skull, and spine. Presentation is location specific. Giant cell tumors = giant multinucleated osteoclast cells. Only 8–15% are malignant. Cyst formation, hemorrhage, necrosis are important with regard to radiosensitivity. Frequent LR (45–60%).Lung metastases common in osteosarcoma, chondrosarcoma, MFH.