Bone Cancers (Osteosarcoma, Ewing’s Sarcoma)

Osteosarcoma arises from osteoblasts, typically in metaphyses of long bones like femur or tibia around the knee, peaking at ages 10-20; Ewing’s sarcoma stems from primitive neuroectodermal cells, often in diaphyses of femur, pelvis, or ribs, more common in children under 15. Osteosarcoma shows osteoid production on biopsy, while Ewing’s features small round blue cells with EWSR1-FLI1 translocation.?

Symptoms and Diagnosis

Both present with localized pain, swelling, limp, fever, or pathologic fractures; imaging (X-ray, MRI, bone scan) and biopsy confirm type, staging metastasis risk to lungs. Elevated ALP marks osteosarcoma; Ewing’s may show onion-skin periosteal reaction.?

Treatment and Prognosis

Neoadjuvant chemotherapy (doxorubicin, cisplatin for osteosarcoma; vincristine, doxorubicin, cyclophosphamide for Ewing’s) shrinks tumors before limb-salvage surgery or amputation; radiation aids Ewing’s. Localized cases achieve 70% 5-year survival, dropping to 30% with metastases; long-term risks include secondary cancers.