osteosarcoma /os′tē·ō′särkō″mə/ [Gk, osteon + sarx, flesh, oma] , a malignant tumor of the bone, composed of anaplastic cells derived from mesenchyme. It is the most common type of primary malignant bone tumor, accounting for 35% of such malignancies. It occurs most often in the distal femur. Metastasis to the lung occurs more often in males than in females. It occurs most frequently between the second and fourth decade of life. Also called osteogenic sarcoma.
