Malignant Bone Tumors

MALIGNANT BONE TUMORS

Primary malignant musculoskeletal tumors are relatively rare and arise from connective and supportive tissue cells (sarcomas) or bone marrow elements. Malignant primary musculoskeletal tumors include osteosarcoma, chondro-sarcoma, Ewing’s sarcoma, and fibrosarcoma. Soft tissue sarcomas include liposarcoma, fibrosarcoma of soft tissue, and rhabdomyo-sarcoma. Bone tumor metastasis to the lungs is common.

Osteogenic sarcoma (osteosarcoma) is the most common and most often fatal primary malignant bone tumor. Prognosis de-pends on whether the tumor has metastasized to the lungs at the time the patient seeks health care. Osteogenic sarcoma appears most frequently in males between the ages of 10 and 25 years (in bones that grow rapidly), in older people with Paget’s disease, and as a result of radiation exposure. Clinical manifestations include pain, swelling, limited motion, and weight loss (which is consid-ered an ominous finding). The bony mass may be palpable, ten-der, and fixed, with an increase in skin temperature over the mass and venous distention. The primary lesion may involve any bone, but the most common sites are the distal femur, the proximal tibia, and the proximal humerus.

Malignant tumors of the hyaline cartilage are called chon-drosarcomas. These tumors are the second most common pri-mary malignant bone tumor. They are large, bulky, slow-growing tumors that affect adults. The usual tumor sites include the pelvis, femur, humerus, spine, scapula, and tibia. Metastasis to the lungs occurs in fewer than half of patients. When these tumors are well differentiated, large bloc excision or amputation of the affected extremity results in increased survival rates. These tumors may recur.